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diff --git a/1000-hours/sounds-of-american-english/4.4-linking.md b/1000-hours/sounds-of-american-english/4.4-linking.md
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--- a/1000-hours/sounds-of-american-english/4.4-linking.md
+++ b/1000-hours/sounds-of-american-english/4.4-linking.md
@@ -1,133 +1,128 @@
-# 4.1 句子
+# 4.4. 连接
-一句话由一个或者多个词汇构成 —— 当一句话由多个词汇构成的时候,有个重要的现象:
+一个**意群**内可能有若干个**单词**,而每个单词都由至少一个音节构成 —— 于是,一连串的音节之间,可能会构成单独朗读时不存在的连接。
-> * 有些词会被**强读**(***accented** form*)
-> * 有些词会被**弱读**(***weak** form*)
+相邻的两个词之间,可能产生的连接通常有以下三种:
-即,不是每个词都是以同样的方式读出来的。
+> 1. 辅音 + 元音
+> 2. 辅音 + 辅音
+> 3. 元音 + 元音
-仔细听听以下例句:
+## 4.4.1 辅音 + 元音(Consonant + Vowel)
-> **TEXT**:
-> * The art of focus in our whirlwind existence can sometimes feel like searching for a needle in a haystack.
-> * The ðɪ art ˈɑːrt of ɒv focus ˈfoʊkəs in ɪn our ˌaʊɚ whirlwind ˈwɝːlwɪnd existence ˈɪɡzɪstəns can kæn sometimes ˈsʌmtaɪmz feel ˈfiːl like ˈlaɪk searching ˈsɝːtʃɪŋ for fɔːr a ə needle ˈniːdəl in ɪn a ə haystack ˈheɪstæk
->
-> **AUDIO**:
-> * 逐字朗读版本
-> * 自然连贯版本
-> * 弱读的词汇:The art *of* focus *in* *our* whirlwind existence *can* sometimes feel *like* searching *for* a needle *in* a haystack.
-> * 相对强读的词汇:The **art** of **focus** in our **whirlwind** existence can **sometimes** **feel** like **searching** for a **needle** in a **haystack**.
+在词汇内部,“辅音 + 元音” 当然可以构成一个音节;在同一个**意群**(thought group)中,如果**以辅音结尾的词汇**遇到**以元音开头的词汇**的话,那么前一个词末尾的**辅音**和后一个词开头的**元音**很可能会连起来读,听起来构成一个**音节**,这种方式叫做**连读**。
-这是一上来就需要调整(或者纠正)的习惯:
+比如在 *People's opinions vary from individual to individual.* 在这句话中,*People's* 末尾的 z 和 *opinions* 开头的 ə 会连在一起,piː·pəl·zə·ˈpɪ·njənz —— 感觉上是在读一整个由 *5* 个音节构成的词汇一样……
-> **不能像词典一样读句子里的每一个单词**。
+这类连读,其实无需刻意,只要做到前面一个词末尾的辅音发声器官动作完整,而后能够熟练且又清楚地说出下一个元音开头的词汇,语音就会自然而然连接起来。
-## 4.1.1. 弱读词汇
+这类**连读**中有相当难度乃至于必须刻意练习的其实只有两种,t 和 l 构成的连读。
-首先要学会的是,把一些 “虚词” —— 根据情况,比如助动词、系动词、介词、连词、冠词、代词等等 —— 弱读。
+之前提到过,在美式英语里,t 有个特殊的现象,它夹在两个元音之间的时候会被浊化,被读成弹舌音,用 t̬ 表示,听起来接近 d…… 比如,在 city ˈsɪt̬i 这个词汇里, t 就夹在两个元音之间,所以读成 t̬。
-比如,在以上的例句中,*of* 不是 ɒv 而是 əv, əf, ə 甚至 ɤ,*in* 不是带着重音的 ˈɪn 而是很轻的 ɪn, ən, *our* 不是 ˌaʊɚ 而是 ɑr,*can* 不是 kæn 而是 kən,*like* laɪk 中的双元音 aɪ 读得很短,*for* 不是 fɔːr 而是 fɚ……
+在自然语流里,同一个意群中,经常会出现以 t 结尾的词汇后面跟着一个以元音开头的词汇,并且,t 的前面是元音的概率也很高,所以,词汇之间出现 t 的浊化弹舌音 t̬ 的情况非常普遍。比如,*Get it done.* ɡet̬ ɪt dʌn
-以下是其中最常见的强读式、弱读式对照列表。
+l 构成的连读,对绝大多数人来说,难点在于,如果前一个单词末尾的 l **舌尖动作不够完整**的话(即,结束的时候舌尖没有贴到龈脊)那么,l 这个弹舌音就发不出来,无法与后面的元音连上…… 尤其是在没有纠正掉用嘴唇动作替代舌尖动作的错误(乃至于有 ʊ 的音色)的情况下。
+
+请仔细听一遍以下的录音,注意所有以 l 作为末尾的音节:
+
+> Whether the *goal of* an insurgency has been to establish the Christian religion in the days of the Roman Empire, to create an interstate commerce commission in nineteenth-century America, or to promote civil rights for minorities in the twentieth century, what a *successful insurgency* does in *institutional or* process terms is to change the incentives and constraints facing others, *as well as* the incentives and constraints facing themselves and their successors.[^1]
+
+在以上这段录音中,*goal‿of*, *successful‿insurgency*, *as well‿as*, 都有前一个单词末尾的 l 与后一个单词开头的元音之间轻微的连读。但,*institutional or* 之间却没有 —— 因为这两个词汇实际上分别属于前后不同的意群。
+
+初学者容易矫枉过正,想把一切自己遇到的词汇间 “辅音 + 元音” 的组合连起来读…… 请注意,是**很可能**连起来读,但**并不一定**。首先,这多少与个人讲话的习惯有关。更为重要的是,讲话的时候要划分**意群**,意群之间要有**暂停**(*pause*)—— 前一个意群末尾的辅音和下一个意群开头的元音,不应该连读。
+
+并且,即便是在同一个意群里,也不能时时刻刻连读,有时盲目连读会出现歧义。
+
+> 比如在这句话之中:
+>
+> * She will cherish those memories and ever hold them close to her heart.
+>
+> 如果 and ever,非要连起来读,前面的 and 可能被弱读作 æn, ən,而后要是非要与后面的 ˈev.ɚ 连起来,就可能被听成 ə.nˈev.ɚ(and never)—— 那岂不是可能会被理解成相反的意思?
> [!Note]
-> 这个列表不能当作**硬规则**使用,不是所有的虚词都必须被弱读;也不是所有的实词都必须被强读 —— 根据情况,这些词在自然语流中也有被强读的时候。
+>
+> 目前(2024.03) OpenAI 的 TTS 引擎生成的语音中,*l + vowels* 的组合总是没有连读效果 —— 也许将来的版本会改进?
-> * a: eɪ → ə
-> * am: æm → əm, m
-> * an: æn → ən, n
-> * and: ænd → ənd, nd, ən, n
-> * any: 'eni → ni
-> * are: /ɑ/: → ə
-> * as: æs → əz
-> * at: æt → ət
-> * but: bʌt → bət
-> * can: kæn → kən, kn, kŋ
-> * could: kud → kəd, kd
-> * do: duː → du, də, d
-> * does: dʌz → dəz
-> * for: fɔː → fə, f
-> * from: frɔm → frəm, frm
-> * had: hæd → həd, əd, d
-> * has: hæz → həz, əz
-> * have: hæv → həv, həf, əv, əf
-> * he: hiː → hi, iː, i
-> * her: həː → hə, əː, ə
-> * him: him → im
-> * his: hiz → iz
-> * I: ai → aː, ə
-> * is: iz → s, z
-> * many: 'meni → mni
-> * me: miː → mi
-> * must: mʌst → məst, məs
-> * my: mai → mi
-> * of: əv → əv, v, f, ə
-> * our: ɑʊɚ → /ɑr ⭢ ɑ/
-> * shall: ʃæl → ʃəl, ʃl
-> * she: ʃiː → ʃi
-> * should: ʃud → ʃəd, ʃd, ʃt
-> * so: səʊ → sə
-> * some: sʌm → səm, sm
-> * such: sʌʧ → səʧ
-> * than: ðæn → ðən, ðn
-> * that: ðæt → ðət
-> * the: /ði/: → ði, ðə
-> * them: ðem → ðəm, ðm, əm, m
-> * then: ðen → ðən
-> * to: tuː → tu, tə, t
-> * us: us → əs
-> * was: wɔz → wəz, wə
-> * we: wiː → wi
-> * were: wəː → wə
-> * when: wen → wən
-> * will: wɪl → /əl, l/
-> * would: wuːd → wəd, əd
-> * you: juː → ju, jə
+## 4.4.2. 辅音 + 辅音(Consonant + Consonant)
-## 4.1.2. 强读词汇
+“**辅音 + 辅音**” 的组合需要注意的地方相对较多。
-事实上,在自然语流中,讲话者经常调整强读(强调)的词汇,用来表达不同的含义。试比较以下同一个句子的 4 个版本[^1],在不同的版本里,被强读的词汇不同:
+## 4.4.2.1 省音(elision)
-> * **Marianna** made the **marmalade**.
-> * **Marianna** made the marmalade.
-> * **Marianna** **made** the **marmalade**.
-> * Marianna made the **marmalade**?
+“**辅音 + 辅音**” 的组合,常常会造成前一个辅音虽然发声器官(*articulator*)动作完整但并不发声的情况,于是会出现一个既 “听不到” 也 “看不见” 的**停顿**(*stop*),之前举过单词内存在这种情况的例子,*hotdog* ˈhɑːtdɑːɡ 和 *network* ˈnetwɝːk,再比如,*hard-nosed* hɑːrd-noʊzd, *partner* ˈpɑːrtnɚ……
-拿第 1 个版本为例,请参照以下图示:
+有人把这种现象叫做 **省音**(*elision*);但,这种说法容易产生误导,因为音的确是省了,但,动作却没省,不仅没有省,**动作还很完整**。
-
+在意群中,更是经常出现前一个词汇末尾是辅音,后一个词汇开头也是辅音的情况 —— 同样会出现**省音**。
-同样一个句子,**强调**不同的**词**可能表达不同的含义[^2]:
+## 4.4.2.2. 叠音(geminates)
-> * Will **you** drive to the office tommorrow? (rather than someone else)
-> * Will you **drive** to the office tommorrow? (rather than going some other way)
-> * Will you drive **to** the office tommorrow? (rather than from the office)
-> * Will you drive to the **office** tommorrow? (rather than somewhere else)
-> * Will you drive to the office **tommorrow**? (rather than some other day)
+上一个音节末尾的辅音和下一个音节开头的辅音相同的时候,这一对相同的辅音被称作**叠音**(*geminates*)。在连贯的自然语音中,这两个辅音就只发声一次 —— 但听起来的时候,有可能感受到前一个辅音存在造成细微停顿。它从机制上来看,其实和**省音**([4.4.2.1](2.4.3-cc#_2-4-3-1-省音-elision))一样。其实哪怕相邻的两个辅音相似的时候,也会发生同样的现象。
-被**强读**的词汇之中,重音音节往往带着**声调** —— 升、降、平、降升。并且,少数重音音节会有被拔高的**音高**。这些都是自然语流的韵律中格外重要的组成部分,也是跟读模仿练习时的重点之一。
+比如,*that time*, 不是 ðæt taɪm/,而是 ðæ·t̬aɪm —— 第一个 t 由于后面跟着一个辅音,于是产生了**省音**,听不到了,但,该有的停顿却依然在,在这里我们用 · 代表那个停顿 ;而后,第二个 t 与第三个 t 是**叠音**,这两个 t 只发声一次。又比如,*bad day*, 不是 bæd deɪ,而是 bæ·deɪ。 再比如,*with this*, 不是 wɪθ ðɪs,而是 wɪ·ðɪs。
-## 4.1.3. 强弱带来的变化
+## 4.4.2.3. 同化(assimilation)
-如果一个音节是重音或被**强读**,那么这个单词中的:
+同化(*assimilation*)主要有两种情况:
-> * 长元音会被读的很清楚,并且足够长,甚至显得更长一些;
-> * 双元音会被读的很饱满,并且显得很有弹性;
-> * 落在重音上的短元音都会显得更长一些;
-> * 重音所在的音节可能带着不同的声调(平调、升调、降调、降升)……
-> * 重音所在的音节可能带着更高的音高(往往是 “高”、“中”、“低” 中的 “高”)……
+> * t + j = tʃ
+> * d + j = dʒ
-如果一个音节被**弱读**,那么这个单词中的:
+最常见的比如,*Don't you?* doʊn tʃju?;以及,*Would you?* wʊ dʒju? 这里的关键在于,t, d 发声时起始的舌尖位置如果放对了([2.2.3](2.2.3-td)),它与后面的 ju 连起来的发声就只能如此。
-> * 长元音会变得短一些(几乎与短元音的长度相当);
-> * 重音音节会变得与非重音音节一样轻;
-> * 很多元音都会发生变化,向 *schwa* ə靠拢;
-> * 很多与辅音相关的停顿会被直接省略;
-> * 清辅音 s、t、k、f 之后的元音 ə 可能会直接被省略掉;
-> * 整个单词所处的音高往往是 “高”、“中”、“低” 之中的 “低”,最多是 “中”……
+同化主要发生在 j 这个音上。除了已经讲过的 j 前面遇到 t 和 d 时会产生同化之外,
-其实,哪怕在单独读某一个单词的时候,其中元音的长短都会受到重音重读的影响。比如,*city* 这个单词,重音在第一个音节上,而两处的元音是一样的:ˈsɪ-t̬ɪ;但是只要你把第一个音节读得足够重,自然而然就能感觉到**第一个音节**只能比**第二个音节**更长。
+> * s + j = ʃ
+> * z + j = ʒ
-[^1] 这个例子来自于 [Macquarie University](https://www.mq.edu.au/about/about-the-university/our-faculties/medicine-and-health-sciences/departments-and-centres/department-of-linguistics/our-research/phonetics-and-phonology/speech/phonetics-and-phonology/Intonation-tobi-introduction)
-[^2] 这个例子来自于 *Manual of American English Pronunciation*, 4th edition, by Clifford H. Prator, Jr. BettyWallaceRobinett, 1972
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+比如,s+j 可能会被读成 ʃ,z+j 可能会被读成 ʒ。再比如,*Miss you so much.* mɪ ʃu səʊ mʌʧ.;*It was your job.* ɪt wɒ ʒʊr ʤɒb.
+
+请注意,这两组是**可能**,并非一定,并非所有英文母语使用者都如此发音。
+
+另外一个细节是,k/g 之前的 n,可能会被同化为 ŋ:
+
+## 4.4.2.4. 击穿(dropping)
+
+“辅音 + 辅音” 的组合中,如果第二个辅音是 h 的话,它常常被击穿(*dropping*),因为 h 原本就是很轻的音,发音时声带并不震动,所以总是自然而然地被前后发音相对更为响亮的声音所掩盖。
+
+比如,*Was he hurt?* 三个单词分开读,应该是 wɒz hi həːt 在连贯的语音中,会被读成 wɒzi həːt —— 听不到 h,它被击穿了。
+
+很多美国人在 t 这个音上还有另外一个特殊的习惯,t 跟在 n 之后的时候,美国人说话的方式会让我们听不到那个 t,也就是说,t 也可能被击穿。比如,他们说 *interview* 的时候你听到的可能是 ˈɪnəˌvju,没有 t。
+
+另外,ð 也可能被击穿,基本只发生在 *them* 这个常用词上。比如,*let them* let ðəm, 变成了 let-əm,又由于 ð 被击穿了之后,t 等于被夹在了两个元音之间,于是会变成浊化的弹舌音 t̬,于是,说出来的或者听到的是 let̬əm…… 所以,在快速的自然语流中 *let him* 和 *let them* 实际上几乎没有区别,需要通过上下文确定究竟是 *him* 还是 *them*。
+
+## 4.4.2.5 其它(others)
+
+值得一提的是,m/n + f/v 的情况。词汇之内我们看过 *comfort* ˈkʌmfɚt 和 *conversation* ˌkɑːnvɚˈseɪʃən 的例子([2.2.13](2.2.13-mnŋ))。这种情况在意群之内也经常会遇到,比如,*stem from*, 只能读成 sten frəm……
+
+## 4.4.3. 元音 + 元音(Vowel + Vowel)
+
+“元音 + 元音” 的组合之中,会出现**加音**(*intrusion*)。
+
+前一个元音以 ɪ/i/iː 结尾,会出现加音 ʲ:
+
+> - *I am* - ˈaɪ ˈæm ⭢ ˈaɪʲæm
+> - *He is* - ˈhiː ˈɪz ⭢ ˈhiːʲɪz
+> - *She is* - ˈʃiː ˈɪz ⭢ ˈʃiːʲɪz
+> - *They are* - ˈðeɪ ˈɑːr ⭢ ˈðeɪʲɑːr
+
+注意:一些以 i 结尾的动词,使用进行时态的时候,末尾会加上 *ing*,即,ɪŋ。比如,*study* ˈstʌdi 的现在分词形式是 *studying* ˈstʌdi.ɪŋ —— 这里会出现加音 ʲ,即最后一个音节变成 jɪŋ…… 可是,在自然读音中,它更接近 jəŋ,所以,*studying* 的读音,词典里标注的当然还是 ˈstʌdiɪŋ,但,读出来的更接近 ˈstʌdiʲəŋ。
+
+再比如:
+
+> *applying* *carrying* *crying*
+>
+> *denying* *qulifying* *replying*
+>
+> *satisfying* *specifying* *spying*
+
+前一个音节以 ʊ 结尾,比如 ʊ/uː/aʊ/oʊ,会出现加音 ʷ:
+
+> - *Go away* - ˈɡoʊ əˈweɪ ⭢ ˈɡoʊʷəˈweɪ
+> - *Do all* - ˈduː ˈɔːl ⭢ ˈduːʷɔːl
+> - *Do it* - ˈduː ˈɪt ⭢ ˈduːʷɪt
+> - *Throw it* - ˈθroʊ ˈɪt ⭢ ˈθroʊʷɪt
+
+
+[^1]: This audio clip is extracted from the Audible edition of Knowledge and Decisions by Thomas Sowell.
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diff --git a/1000-hours/sounds-of-american-english/4.5-sentences.md b/1000-hours/sounds-of-american-english/4.5-sentences.md
index e69de29b..f69c62aa 100644
--- a/1000-hours/sounds-of-american-english/4.5-sentences.md
+++ b/1000-hours/sounds-of-american-english/4.5-sentences.md
@@ -0,0 +1,133 @@
+# 4.5. 句子
+
+一句话由一个或者多个词汇构成 —— 当一句话由多个词汇构成的时候,有个重要的现象:
+
+> * 有些词会被**强读**(***accented** form*)
+> * 有些词会被**弱读**(***weak** form*)
+
+即,不是每个词都是以同样的方式读出来的。
+
+仔细听听以下例句:
+
+> **TEXT**:
+> * The art of focus in our whirlwind existence can sometimes feel like searching for a needle in a haystack.
+> * The ðɪ art ˈɑːrt of ɒv focus ˈfoʊkəs in ɪn our ˌaʊɚ whirlwind ˈwɝːlwɪnd existence ˈɪɡzɪstəns can kæn sometimes ˈsʌmtaɪmz feel ˈfiːl like ˈlaɪk searching ˈsɝːtʃɪŋ for fɔːr a ə needle ˈniːdəl in ɪn a ə haystack ˈheɪstæk
+>
+> **AUDIO**:
+> * 逐字朗读版本
+> * 自然连贯版本
+> * 弱读的词汇:The art *of* focus *in* *our* whirlwind existence *can* sometimes feel *like* searching *for* a needle *in* a haystack.
+> * 相对强读的词汇:The **art** of **focus** in our **whirlwind** existence can **sometimes** **feel** like **searching** for a **needle** in a **haystack**.
+
+这是一上来就需要调整(或者纠正)的习惯:
+
+> **不能像词典一样读句子里的每一个单词**。
+
+## 4.5.1. 弱读词汇
+
+首先要学会的是,把一些 “虚词” —— 根据情况,比如助动词、系动词、介词、连词、冠词、代词等等 —— 弱读。
+
+比如,在以上的例句中,*of* 不是 ɒv 而是 əv, əf, ə 甚至 ɤ,*in* 不是带着重音的 ˈɪn 而是很轻的 ɪn, ən, *our* 不是 ˌaʊɚ 而是 ɑr,*can* 不是 kæn 而是 kən,*like* laɪk 中的双元音 aɪ 读得很短,*for* 不是 fɔːr 而是 fɚ……
+
+以下是其中最常见的强读式、弱读式对照列表。
+
+> [!Note]
+> 这个列表不能当作**硬规则**使用,不是所有的虚词都必须被弱读;也不是所有的实词都必须被强读 —— 根据情况,这些词在自然语流中也有被强读的时候。
+
+> * a: eɪ → ə
+> * am: æm → əm, m
+> * an: æn → ən, n
+> * and: ænd → ənd, nd, ən, n
+> * any: 'eni → ni
+> * are: /ɑ/: → ə
+> * as: æs → əz
+> * at: æt → ət
+> * but: bʌt → bət
+> * can: kæn → kən, kn, kŋ
+> * could: kud → kəd, kd
+> * do: duː → du, də, d
+> * does: dʌz → dəz
+> * for: fɔː → fə, f
+> * from: frɔm → frəm, frm
+> * had: hæd → həd, əd, d
+> * has: hæz → həz, əz
+> * have: hæv → həv, həf, əv, əf
+> * he: hiː → hi, iː, i
+> * her: həː → hə, əː, ə
+> * him: him → im
+> * his: hiz → iz
+> * I: ai → aː, ə
+> * is: iz → s, z
+> * many: 'meni → mni
+> * me: miː → mi
+> * must: mʌst → məst, məs
+> * my: mai → mi
+> * of: əv → əv, v, f, ə
+> * our: ɑʊɚ → /ɑr ⭢ ɑ/
+> * shall: ʃæl → ʃəl, ʃl
+> * she: ʃiː → ʃi
+> * should: ʃud → ʃəd, ʃd, ʃt
+> * so: səʊ → sə
+> * some: sʌm → səm, sm
+> * such: sʌʧ → səʧ
+> * than: ðæn → ðən, ðn
+> * that: ðæt → ðət
+> * the: /ði/: → ði, ðə
+> * them: ðem → ðəm, ðm, əm, m
+> * then: ðen → ðən
+> * to: tuː → tu, tə, t
+> * us: us → əs
+> * was: wɔz → wəz, wə
+> * we: wiː → wi
+> * were: wəː → wə
+> * when: wen → wən
+> * will: wɪl → /əl, l/
+> * would: wuːd → wəd, əd
+> * you: juː → ju, jə
+
+## 4.5.2. 强读词汇
+
+事实上,在自然语流中,讲话者经常调整强读(强调)的词汇,用来表达不同的含义。试比较以下同一个句子的 4 个版本[^1],在不同的版本里,被强读的词汇不同:
+
+> * **Marianna** made the **marmalade**.
+> * **Marianna** made the marmalade.
+> * **Marianna** **made** the **marmalade**.
+> * Marianna made the **marmalade**?
+
+拿第 1 个版本为例,请参照以下图示:
+
+
+
+同样一个句子,**强调**不同的**词**可能表达不同的含义[^2]:
+
+> * Will **you** drive to the office tommorrow? (rather than someone else)
+> * Will you **drive** to the office tommorrow? (rather than going some other way)
+> * Will you drive **to** the office tommorrow? (rather than from the office)
+> * Will you drive to the **office** tommorrow? (rather than somewhere else)
+> * Will you drive to the office **tommorrow**? (rather than some other day)
+
+被**强读**的词汇之中,重音音节往往带着**声调** —— 升、降、平、降升。并且,少数重音音节会有被拔高的**音高**。这些都是自然语流的韵律中格外重要的组成部分,也是跟读模仿练习时的重点之一。
+
+## 4.5.3. 强弱带来的变化
+
+如果一个音节是重音或被**强读**,那么这个单词中的:
+
+> * 长元音会被读的很清楚,并且足够长,甚至显得更长一些;
+> * 双元音会被读的很饱满,并且显得很有弹性;
+> * 落在重音上的短元音都会显得更长一些;
+> * 重音所在的音节可能带着不同的声调(平调、升调、降调、降升)……
+> * 重音所在的音节可能带着更高的音高(往往是 “高”、“中”、“低” 中的 “高”)……
+
+如果一个音节被**弱读**,那么这个单词中的:
+
+> * 长元音会变得短一些(几乎与短元音的长度相当);
+> * 重音音节会变得与非重音音节一样轻;
+> * 很多元音都会发生变化,向 *schwa* ə靠拢;
+> * 很多与辅音相关的停顿会被直接省略;
+> * 清辅音 s、t、k、f 之后的元音 ə 可能会直接被省略掉;
+> * 整个单词所处的音高往往是 “高”、“中”、“低” 之中的 “低”,最多是 “中”……
+
+其实,哪怕在单独读某一个单词的时候,其中元音的长短都会受到重音重读的影响。比如,*city* 这个单词,重音在第一个音节上,而两处的元音是一样的:ˈsɪ-t̬ɪ;但是只要你把第一个音节读得足够重,自然而然就能感觉到**第一个音节**只能比**第二个音节**更长。
+
+[^1] 这个例子来自于 [Macquarie University](https://www.mq.edu.au/about/about-the-university/our-faculties/medicine-and-health-sciences/departments-and-centres/department-of-linguistics/our-research/phonetics-and-phonology/speech/phonetics-and-phonology/Intonation-tobi-introduction)
+[^2] 这个例子来自于 *Manual of American English Pronunciation*, 4th edition, by Clifford H. Prator, Jr. BettyWallaceRobinett, 1972
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