23.77億語コーパス／全数走査／2026-08-26

that節の前で消える前置詞

be aware of A は be aware that S+V になる。この「of が抜ける」現象を、 1億6,457万文を1件残らず数えて確かめた。結論から言うと、これは of だけの癖ではなく 英語の前置詞ぜんぶに効く規則で、例外は数えるほどしかない。

be aware of that it is dangerous → be aware that it is dangerous

of + that節＝819件／全 that節 11,862,089件（0.007%。しかもほぼ全部が誤タグ）

走査文数: 164,573,969
語数: 23.77億
接続詞 that: 11,862,089
of の出現: 55,738,386
of + that節: 819

結論

英語の前置詞は、that節を目的語にできない。だから前置詞つきの語が that節をとるとき、前置詞は必ず落ちる。of は 55,738,386回出るが、直後が that節なのは 819回（0.0015%）。語ごとに見ると be aware of → be aware that の脱落率は 99.79%、 remind O of → remind O that は 99.95%、be ashamed of → be ashamed that は 100.00%。
of だけではない。on / about / for / to / at / with / in / from / by / against … 調べた主要前置詞すべてで同じことが起きる。insist on → insist that（脱落率 99.85%）、 worry about → worry that、hope for → hope that、object to → object that、 surprised at → surprised that、satisfied with → satisfied that、 confident in → confident that、infer from → infer that。
消えるのは that節の前だけ。名詞句・動名詞・wh節・whether節の前では前置詞は残る。 of の内訳は名詞句 46,164,265 ／動名詞 1,843,965 ／ wh節 669,026 ／ whether節 20,415 に対し、 that節 819。この非対称が現象の正体で、「that節だけが前置詞の目的語になれない」という一点に尽きる。
本物の例外は2つだけ。in that（〜という点で・23,378件）と except that（14,130件）。文語・法律文の notwithstanding that（145件）と save that（約400件）を足しても4つ。 so that / now that / given that などは前置詞ではなく接続詞。
前置詞を残したいときは名詞をはさむ。P + the fact that 型が 677,610件。 due to the fact that／despite the fact that／in the sense that。ほかに see to it that（2,897件）、wh節なら as to whether。

01前置詞別の脱落率

各前置詞が出てきたとき、直後に接続詞の that が立つ割合。語のリストを一切使わず、コーパス中の前置詞トークンを全部数えた。

前置詞	総出現	＋名詞句	＋動名詞	＋wh節	＋whether節	＋名詞＋that	＋that節	that率
of	55,738,386	46,164,265	1,843,965	669,026	20,415	36,222	819	0.0015%
from	9,647,205	7,252,833	422,800	149,606	200	9,147	168	0.0017%
under	1,112,297	987,313	10,413	13,193	2	7,435	24	0.0022%
for	20,693,305	14,667,079	1,040,201	263,942	957	14,952	498	0.0024%
against	1,290,650	1,004,612	21,848	8,714	23	1,442	38	0.0029%
during	1,148,486	1,045,091	12,741	16,934	0	31	36	0.0031%
between	1,592,358	1,124,227	29,580	9,481	172	138	52	0.0033%
at	11,430,193	8,864,524	156,489	133,668	1,666	9,173	514	0.0045%
into	3,676,852	3,128,569	87,545	28,525	2,183	2,063	269	0.0073%
to	22,452,456	16,465,516	566,073	285,350	15,255	45,405	1,761	0.0078%
with	17,068,989	12,934,141	321,829	142,049	1,151	30,183	1,965	0.0115%
by	8,467,333	6,493,060	986,404	64,353	512	18,011	1,136	0.0134%
on	15,913,001	13,273,371	308,521	250,273	21,611	21,329	3,264	0.0205%
about	5,651,524	2,980,317	365,788	376,496	25,176	15,253	7,023	0.1243%
in ★	41,152,964	34,928,809	748,280	395,428	1,023	35,977	23,378	0.0568%
besides △	58,191	32,374	9,296	1,257	6	834	380	0.6530%
except ★	214,057	52,815	2,678	8,476	11	221	14,130	6.6010%
so ☆	802,409	89,628	1,336	1,242	295	125	222,374	27.7133%

★＝本物の例外（→ 03）　△＝besides の 380件は「そのほかに」の副詞＋指示代名詞が大半で、本物の例外とは言えない　☆＝so that は前置詞ではなく接続詞。「that率」は間引きなしの実測値。

読み方。ふつうの前置詞の that率は 0.002〜0.02% の帯に収まる。 5万回に1回あるかないか、という水準で、これは実質ゼロ。一方で同じ前置詞が wh節・whether節・動名詞は数十万件単位で従える。 「前置詞が節を嫌う」のではなく「that節だけがダメ」だとわかる。

02残った数百件は本物か

of の 819件、for の 498件は何なのか。that の2語前まで文脈を数えると、正体がはっきり出る。

2語文脈の表はフラッシュ単位で1回きりの文脈を落とす設計のため**下限値**。1語文脈（819 など）と前置詞別の総数は間引きなしの実測。
見かけの形	実際に多い文脈	正体
of that	result of that 59／top of that 24／aware of that 17／spite of that 4	as a result of that／on top of that＝指示代名詞。句読点の欠落で次の文とつながり、that が接続詞に誤タグされた
about that	talk about that 638／talking 573／talked 487／worry 311	talk about that＝指示代名詞
on that	early on that 739／going on that 730／let on that 240	decided early on that …＝副詞句 early on＋that節。on は that を支配していない
by that	goes by that 372／went by that 67	not a day goes by that …＝関係詞
than that	other than that 2,261／more than that 426	other than that, …＝副詞句
like that	i like that 1,122／n't like that 769／something like that 350	動詞 like ＋ that節／指示代名詞
before / after that	said before that 338／shortly after that 100	副詞の before that / after that
in that	unique / unusual / different / lucky / similar が上位（実数は 03）	本物。「〜という点で」の接続詞 in that

誤タグの例 of + that

That day when I hugged her I wasn't aware of that she was standing miles away from me.

↑ 非母語話者の書き誤り。むしろ規則の存在を裏づける

副詞句の例 on + that

Dubber, the officer who chose the Albany site, insisted early on that he wanted no wildlife disturbed unnecessarily.

↑ early on ＋ that節。insist on that ではない

つまり。純粋に「前置詞が that節を直接とった」と言える例は、23億語を全部見ても in that / except that / besides that 以外にほぼ存在しない。 of・for・at・from の残余はすべてタグ付けの誤りか、別構造の見間違い。

03本物の例外は2つ

that節を直接とれる「前置詞」は、実質この2語だけ。いずれも接続詞化した用法として辞書に載る。

in that 23,378件

Lillypads are unique in that they are intended to not be an unlimited, uniform size.

unique 737 ／ unusual 435 ／ different 249 ／ lucky 195 ／ similar 178 ／ differ 177 ／ interesting 149 ／ right 144 ／ correct 127

except that 14,130件

Credit unions are similar to commercial banks, except that they are membership-owned nonprofits.

直前は「,」が 6,458件。同一性を述べたあと差分を足す型

これ以外は残らない。notwithstanding that（145件・法律文）と save that（約400件・文語）がかろうじて本物だが、教材で扱う頻度ではない。besides that（380件）は「,／but／and ＋ besides that」の並びが上位を占め、「そのほかに」の副詞＋指示代名詞が大半。 despite that（355件）も同様に「,＋despite that」が最多で、副詞用法。

紛らわしいが前置詞ではないもの。that節を従えるが、これらは分詞・副詞由来の接続詞であり、「前置詞＋that節」の反例にはならない。 so that222,374 now that120,151 such that34,774 given that20,092 assuming that14,203 seeing that8,044 considering that7,395 provided that4,739 notwithstanding that145

04of で起きる語 ― 形容詞

「脱落率」＝ that節をとった回数のうち、前置詞が付いていない割合。 100%に近いほど「前置詞は必ず消える」。

見出し	形	of＋名詞句	of＋動名詞	that節	of＋that節	脱落率	of＋the fact that
aware	be aware of A / that S	56,313	1,591	26,371	56	99.79%	1,615
afraid	be afraid of A / that S	43,307	9,830	13,737	10	99.93%	35
proud	be proud of A / that S	37,785	1,183	2,578	6	99.77%	530
sure	be sure of A / that S	11,880	557	116,985	78	99.93%	78
certain	be certain of A / that S	3,295	176	16,030	14	99.91%	39
ashamed	be ashamed of A / that S	8,603	942	711	0	100.00%	42
conscious	be conscious of A / that S	5,264	540	1,206	5	99.59%	293
suspicious	be suspicious of A / that S	4,231	52	755	9	98.82%	18
mindful	be mindful of A / that S	2,547	158	587	3	99.49%	169
fearful	be fearful of A / that S	2,133	700	985	2	99.80%	11
ignorant	be ignorant of A / that S	2,136	26	74	4	94.87%	118
convinced	be convinced of A / that S	631	16	7,401	10	99.87%	55
reminded	be reminded of A / that S	4,084	66	1,649	4	99.76%	51
informed	be informed of A / that S	2,735	33	3,484	15	99.57%	55
assured	be assured of A / that S	795	142	2,007	3	99.85%	6
notified	be notified of A / that S	1,355	22	697	11	98.45%	4

of ＋名詞句 56,313件

Merkulov said they are aware of the national and global spotlight on the industry.

of が消えて that節 26,371件

Ironically, the allied high command was well aware that the Communists were on the move somewhere.

05of で起きる語 ― 動詞＋O

remind O of A → remind O that S。目的語をはさんでも同じことが起きる。数え方は「目的語の名詞句をまたいだ位置」で統一した。

見出し	形	O＋of＋名詞句	O＋that節	O＋of＋that節	脱落率	O＋of＋wh/whether
remind	remind O of A / that S	41,391	21,556	11	99.95%	5,111
convince	convince O of A / that S	3,616	18,300	8	99.96%	160
inform	inform O of A / that S	8,236	14,919	26	99.83%	601
assure	assure O of A / that S	2,340	13,947	5	99.96%	26
warn	warn O of A / that S	3,876	8,564	27	99.69%	163
notify	notify O of A / that S	2,514	1,343	19	98.60%	53
persuade	persuade O of A / that S	688	1,908	3	99.84%	12
advise	advise O of A / that S	1,527	1,715	8	99.54%	42

of ＋名詞句 41,391件

Jeff Flake of Arizona said seeing the lawmakers tending to the injured reminded him of the shooting of Rep.

of が消えて that節 21,556件

Shoba is here to remind us that good heart health begins when we are born.

「of をとる動詞なら必ず that節も使える」わけではない。 accuse O of A は 42,328件（動名詞 30,693件）あるのに that節はわずか 66件、 suspect O of A は 4,546件に対し that節 53件。 of＋名詞句／動名詞しか持たない動詞は、that節そのものを取らない。 「that節をとる語かどうか」と「of をとるかどうか」は別の情報で、両方を持つ語だけが脱落を起こす。

06of で起きる語 ― 名詞

名詞でも同じ。the possibility of A は the possibility that S になる。同格の that節の正体はこれ。

名詞は shell noun（内容が that節で埋まる名詞）に限って集計。関係詞の that を巻き込みにくいのがこの群。
見出し	of＋名詞句	of＋動名詞	that節	of＋that節	脱落率
the idea of / that	91,521	31,260	49,363	128	99.74%
the sign of / that	87,711	7,690	15,696	48	99.70%
the chance of / that	65,918	34,789	15,879	39	99.75%
the evidence of / that	55,525	1,965	42,021	101	99.76%
the possibility of / that	50,713	16,567	25,804	27	99.90%
the thought of / that	42,085	13,696	6,798	56	99.18%
the fear of / that	37,965	10,690	10,768	34	99.69%
the knowledge of / that	38,867	740	3,479	48	98.64%
the feeling of / that	34,338	5,298	18,993	64	99.66%
the hope of / that	25,726	17,119	20,736	24	99.88%
the proof of / that	25,583	374	12,630	15	99.88%
the notion of / that	25,317	2,602	12,693	8	99.94%
the news of / that	17,791	333	10,463	98	99.07%
the impression of / that	8,377	747	10,655	22	99.79%
the suspicion of / that	7,770	1,948	3,622	9	99.75%
the assumption of / that	7,182	170	13,087	16	99.88%

07of 以外の前置詞

質問の核心。答えは「of 以外でも全部起きる」。機械スクリーニング（that節も前置詞句も十分な頻度で持つ語）を通ったのは 237語。そのうち教材にしやすいものを前置詞別に並べる。

on ― insist on / decide on / agree on

形	P＋名詞句	P＋動名詞	that節	P＋that節	脱落率
insist on A / insist that S	20,459	13,842	23,210	36	99.85%
decide on A / decide that S	10,478	527	39,979	68	99.83%
agree on A / agree that S	11,669	410	35,888	163	99.55%
comment on A / comment that S	24,747	449	5,746	39	99.33%
speculate on A / speculate that S	1,747	21	7,333	10	99.86%
remark on A / remark that S	964	23	4,085	6	99.85%

on ＋名詞句 20,459件

The Indian side insists on a second-generation engine, whereas Russia uses first-stage engines for its aircraft.

on が消えて that節 23,210件

The Irish government branded the view "bizarre" and insisted that an agreement is binding.

about ― worry about / complain about

*worry* の 449件は「worry about **that**（指示代名詞）」の誤タグが大半（→ 02）。
形	P＋名詞句	P＋動名詞	that節	P＋that節	脱落率
worry about A / worry that S	73,026	10,269	10,650	449	95.95%
be worried about A / worried that S	48,266	6,260	10,232	65	99.37%
be concerned about A / that S	29,201	3,021	9,949	38	99.62%
complain about A / complain that S	19,619	1,717	9,082	48	99.47%
be sorry about A / sorry that S	10,650	847	8,107	59	99.28%
the concern about A / concern that S	26,711	1,926	12,390	48	99.61%
the doubt about A / doubt that S	9,414	377	16,317	42	99.74%
be anxious about A / anxious that S	1,947	382	495	0	100.00%
brag about A / brag that S	3,937	831	592	8	98.67%

for / to

形	P＋名詞句	that節	P＋that節	脱落率
hope for A / hope that S	3,812	40,597	24	99.94%
pray for A / pray that S	18,469	8,844	49	99.45%
wish for A / wish that S	7,341	12,396	15	99.88%
be grateful for A / grateful that S	11,828	4,589	7	99.85%
be thankful for A / thankful that S	4,117	2,851	2	99.93%
be sorry for A / sorry that S	30,927	8,107	59	99.28%
provide for A / provide that S	13,570	7,373	19	99.74%
admit to A / admit that S	21,268	34,642	35	99.90%
confess to A / confess that S	9,485	4,134	10	99.76%
swear to A / swear that S	12,484	4,873	10	99.80%
testify to A / testify that S	2,220	6,040	21	99.65%
object to A / object that S	8,257	248	9	96.50%
attest to A / attest that S	1,521	525	2	99.62%
be clear to O / clear that S	12,892	49,236	209	99.58%
be obvious to O / obvious that S	3,757	10,534	26	99.75%

at / with / in / from / by / against

*argue* は with 15,266 ／ for 5,168 ／ about 3,899 ／ against 3,486 ／ over 1,501 と5通りの前置詞をとるが、 that節（67,331件）ではそのどれも現れない。**前置詞が何であれ that節の前では消える**。
※ 1つの見出しが複数の前置詞をとる場合、「that節」「P＋that節」「脱落率」は見出し単位の値なので、その語の行はどの前置詞の表でも同じ数字になる（argue / clear / surprised / sorry / agree）。
前置詞	形	P＋名詞句	that節	P＋that節	脱落率
at	be surprised at A / surprised that S	4,881	10,844	23	99.79%
at	be amazed at A / amazed that S	2,042	1,898	4	99.79%
at	hint at A / hint that S	4,406	3,646	19	99.48%
at	marvel at A / marvel that S	3,234	484	0	100.00%
at	be angry at A / angry that S	10,041	3,189	24	99.25%
with	be satisfied with A / satisfied that S	10,825	3,321	16	99.52%
with	be pleased with A / pleased that S	11,511	4,096	14	99.66%
with	be happy with A / happy that S	24,790	10,108	79	99.22%
with	agree with A / agree that S	76,971	35,888	163	99.55%
with	be disappointed with A / that S	1,053	2,234	5	99.78%
in	be confident in A / confident that S	5,589	14,874	24	99.84%
in	believe in A / believe that S	76,812	201,414	156	99.92%
from	infer from A / infer that S	2,489	1,989	1	99.95%
from	deduce from A / deduce that S	1,149	1,869	0	100.00%
from	gather from A / gather that S	2,072	1,305	17	98.71%
from	be clear from A / clear that S	3,870	49,236	209	99.58%
from	be evident from A / evident that S	1,468	4,467	15	99.67%
by	be surprised by A / surprised that S	2,959	10,844	23	99.79%
by	be confirmed by A / confirmed that S	12,338	2,361	8	99.66%
by	be suggested by A / suggested that S	2,487	8,685	3	99.97%
against	warn O against A / warn O that S	1,450	8,564	27	99.69%
against	argue against A / argue that S	3,486	67,331	69	99.90%
against	protest against A / protest that S	3,467	987	6	99.40%

with ＋名詞句 10,825件

Both owners and players seem to be satisfied with their share of a pie that keeps getting bigger.

with が消えて that節 3,321件

Wells Fargo won't be allowed to get any bigger until the Fed is satisfied that it has cleaned up its act.

from ＋名詞句 2,489件

As you might infer from the name, it is a soccer channel.

from が消えて that節 1,989件

Therefore we cannot conclude from this study that using antiseptic soap while pregnant makes children fat.

※ from句が副詞的に残る場合は共存できるが、from が that節を支配することはない

08前置詞が生き残る場所

同じ語で「that節の前では消える／wh節・動名詞の前では残る」を並べると、規則の輪郭が出る。ここが授業で一番効く対比。

「前置詞保持率」＝ wh節・whether節をとったうち前置詞が付いている割合。**that節ではほぼ0%、wh節では75〜90%**。
見出し	of＋wh/whether	前置詞なしの wh	前置詞保持率	of＋that節	前置詞脱落率
be mindful of	396	48	89.2%	3	99.49%
be proud of	3,106	402	88.5%	6	99.77%
be aware of	8,758	1,281	87.2%	56	99.79%
marvel at	908	135	87.1%	0	100.00%
be ashamed of	852	181	82.5%	0	100.00%
be worried about	4,117	1,118	78.6%	65	99.37%
be concerned about	3,138	917	77.4%	38	99.62%
worry about	6,244	1,945	76.2%	449	95.95%
be afraid of	3,392	1,157	74.6%	10	99.93%
agree with	2,983	1,033	74.3%	163	99.55%
depend on	41,817	5,560	88.3%	29	—

of の全内訳（55,738,386件）。 名詞句 46,164,265／動名詞 1,843,965／wh節 669,026／whether節 20,415／名詞をはさんだ that節 36,222／直接の that節 819。前置詞は名詞相当のものなら何でもとれる。that節だけが名詞相当として振る舞えない。

wh節の前 ― of は残る

He was still plenty involved with his team, still more than aware of what was and wasn't working.

that節の前 ― of は消える

The allied high command was well aware that the Communists were on the move somewhere.

09逃げ道① ― P ＋名詞＋ that

どうしても前置詞を残したいときは、間に名詞を1つ入れて that節をその名詞の同格にする。この型は語彙リストを使わずに全数で数えて 677,610件。

「固着度」＝その「前置詞＋名詞」が出たとき that が続く割合。高いほど熟語として固まっている。 *on the ground* のように地面の意味と同形のものは低く出る。
形	件数	固着度	意味
to the fact that	19,228	82.9%	due to / owing to / attributable to
of the fact that	13,986	72.1%	aware of / in spite of / regardless of
despite the fact that	12,375	85.0%	〜にもかかわらず
in the sense that	12,094	60.0%	〜という意味で
by the fact that	12,016	88.1%	〜という事実によって
about the fact that	10,988	85.1%	〜という事実について
with the fact that	9,839	80.9%	deal with / cope with
on the fact that	6,459	75.1%	based on / rely on
from the fact that	5,766	85.4%	〜という事実から
for the fact that	5,530	84.0%	〜という事実に対して
to the conclusion that	5,340	75.8%	come to / lead to the conclusion that
to the extent that	4,361	44.6%	〜する程度まで／〜する限り
in the hope that	3,941	41.2%	〜を期待して
on the ground(s) that	3,077	2.6%	〜という理由で
under the assumption that	2,875	63.8%	〜と仮定して
on the assumption that	2,348	73.9%	〜という前提で
under the impression that	2,065	66.2%	〜だと思い込んで
in order that	2,160	0.8%	〜するように（目的）
in the event that	1,671	9.5%	〜する場合には
of the opinion that	1,614	69.7%	〜という意見である
on the basis that	1,492	5.3%	〜という根拠で
on the condition that	1,351	36.6%	〜という条件で
into account that	1,415	3.4%	take into account that 〜を考慮に入れる
P ＋名詞＋ that 全体	677,610	—	うち名詞が fact のもの 117,417件

the fact that の正体。fact ＋ that節は全部で 269,436件あり、そのうち 117,417件（43.6%）は直前に前置詞が立っている。つまり the fact that の4割強は「前置詞を残すための台座」として使われている。 due to the fact that が because の重い言い換えとして嫌われるのは、この機能語的な使い方が理由。

前置詞は残せない

× ... despite that Ding was dazed and bloodied ...

名詞をはさむと残せる 12,375件

Despite the fact that Ding was dazed, bloodied and confused at the end, the referee declared the affair a "tie."

10逃げ道② ― it をはさむ / as to

see to it that ― 形式目的語の it を置く

前置詞の目的語の位置に it を置き、その中身を that節で後置する型。実用的な広がりはほぼ see to it that 1本に集約される（2,897件。 to ＋ it ＋ that 全体で 3,586件）。

see to it that 2,897件

He said he would see to it that the institute continues its mission "if it takes my last dollar."

see to it that

"President, please see to it that there is no war because my region will suffer immensely," Duterte said.

as to ＋ wh ― 前置詞が二重になる型

wh節・whether節なら前置詞は残せるが、その前置詞が言いにくいとき as to で受ける。 that節にはこの手が使えない（as to that S+V は存在しない）。

as to what15,462 as to whether12,395 as to why11,204 as to how9,536 as to who3,367 as to where3,055 as to when1,392 as to which1,385

※ 2語文脈の集計のため下限値（高頻度の型では影響は無視できる）。

as to whether

The question as to whether animals feel emotions has been argued for years.

on ＋ whether

The answer depends on whether you think the federal government can play a catalytic role.

11そもそも that節を取れない語

前置詞が消えるのは「その語が that節も取れる」場合だけ。取れない語は、前置詞を残したまま逃げ道を使うか、wh節に逃げる。ここを混ぜると生徒が誤作文する。

この群は「脱落率」を出しても意味がない（分母の that節そのものが数十件しかない）。前置詞を保持したまま **the fact that** か **whether/wh節** に逃げるのが実際の解。
形	P＋名詞句	P＋wh/whether	P＋名詞＋that	裸の that節	実際の言い方
depend on	148,593	41,817	179	22	It depends on whether … ／ × depends that
be based on	92,901	1,744	3,281	9	based on the fact that …
rely on	67,975	543	631	27	rely on the fact that …
deal with	202,295	3,589	895	52	deal with the fact that …
be interested in	100,895	4,980	180	169	interested in whether / what …
be responsible for	104,918	2,385	91	48	responsible for the fact that …
be consistent with	58,747	1,302	2,087	151	consistent with the idea that …
accuse O of	42,328	94	2	66	accuse O of doing（動名詞 30,693件）
result in	133,569	293	290	177	result in 名詞句 / 動名詞

depend on ＋ whether

He says the admittance of economic migrants depends on whether European labor markets can absorb them.

based on ＋ the fact that

I think the powers that be would like me to do it in the US based on the fact that I have a high profile there.

12授業でどう言うか

数字を生徒に見せる必要はない。ルールを1行にすると次の形になる。

「英語の前置詞は that節を目的語にできない。だから that節が来ると前置詞は消える。」

覚えるのは語ごとではなく規則。「aware of なのに aware that になるのはなぜ」ではなく、「that節の前では前置詞は全部消える」。remind O of A → remind O that S も、insist on A → insist that S も、 surprised at A → surprised that S も同じ1つの規則。
wh節と比べさせる。I'm aware of what he did. ／ I'm aware that he did it. wh節は名詞のかたまりとして前置詞の後ろに置ける。that節は置けない。この対比が一番効く。
どうしても前置詞を残したいときは the fact をはさむ。 in spite of the fact that S／due to the fact that S。ただし冗長なので、書かせるなら although / because に寄せる。
例外は3つだけ暗記させる。in that（〜という点で）・except that（〜という点を除いて）・ see to it that（〜するよう取り計らう）。so that / now that / given that は前置詞ではないので別扱い。
逆向きの誤りに注意。depend / be based / rely / deal with は that節そのものを取れない。× It depends that … は It depends on whether … に直す。

13方法とデータ

コーパス。ローカルの均衡英語コーパス（23.77億語／1億6,457万文／29.2億トークン）。字幕・現代小説・報道・Wikipedia・Common Crawl・Reddit・医学論文・arXiv 抄録・放送インタビュー（MediaSum）・話し言葉コーパス（BNC 等）の9〜11ソース構成。 spaCy で品詞・レンマ・PTBタグを全文付与済み。

走査。サンプリングなしの全数走査を2パス。第1パスは前置詞トークンの直後に何が来るかと、主要語（形容詞／be＋過去分詞／動詞／名詞）の補部フレーム。第2パスは語彙リストを使わず「接続詞 that の直前に立つ語」を全数で数え、あわせて「前置詞＋名詞＋that」を網羅した。 12並列で各パス約25分。API 不使用・完全ローカル・決定論（同じコーパスなら毎回同じ値）。

that の見分け。接続詞の that は PTBタグ IN、指示語は DT、関係詞は WDT。IN だけを数えた。 that の直後がすぐ定形動詞になるものは関係詞読みとして別枠にした（62,931件）。 so / such / too … that の結果節も、主要語の左5語に so/such/too があれば別枠にして除外している（除外しないと程度形容詞が全部「that節をとる語」になってしまう）。

数値の出どころ。前置詞別の総数・語別の件数・「that の直前語」は一切間引いていない実測値。「that の2語前の文脈」と「as to ＋ wh」の内訳だけは、フラッシュ単位で1回きりの文脈を落とす設計のため 下限値。2つのパスは前後を見る窓の取り方が違うので、同じ形でも数%ずれることがある（本文の「前置詞＋名詞＋that」は第2パスの値で統一）。

限界。(1) 目的格の関係詞（the idea that he proposed）はトークン列だけでは同格の that節と区別できないため、名詞は shell noun に限って読んでいる。(2) that が省略された節（I'm sure he's right）は主格代名詞＋定形動詞という控えめな条件でしか拾っていないので、実数はもっと多い。どちらの限界も「前置詞が消える」という結論の向きを変えない。

成果物。C:\JC_EDU\_catalog\prep_drop\ ― prepdrop.db（frame 1,022万キー・head_total 317万キー）／ thatctx.db／tables\前置詞脱落_全数調査.xlsx（全7シート）／ scripts\（再現一式）／README.md。

結論