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1000-hours/sounds-of-american-english/draft.md

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 # Sounds of American English
 
-## 00. Introduction
+## Introduction
 
-## 01. English Alphabet
+## 1. English Alphabet
 
 Modern English is composed of *26* letters, each with both *uppercase* and *lowercase* forms. English stands out among European languages for not using [diacritics](https://en.wikipedia.org/wiki/Diacritic), which are special marks added to letters to alter their pronunciation or meaning, such as *â*, *é* or *ç*, etc.
 
@@ -43,3 +43,27 @@ In British, letter *z* is pronounced as `/zed/`。
 >
 > 1. The synthesized audio files primarily utilizes OpenAI's TTS (Text-to-Speech) and Microsoft Edge's TTS. The blue speaker icon<span class="speak-word-inline" data-audio-us="/audios/us/Alpha-us-guy.mp3"></span>represents a male voice, whereas the brown speaker icon<span class="speak-word-inline" data-audio-uk="/audios/us/Alpha-us-jen.mp3"></span>signifies a female voice.
 > 2. The IPA ([International Phonetic Alphabet](https://en.wikipedia.org/wiki/International_Phonetic_Alphabet)) notation used for phonetic transcription is generated by OpenAI's ChatGPT, which may occasionally make mistakes that need to be corrected.
+
+## 2. Phonemes
+
+In natural speech, indivisible sound segments are referred to as *phonemes*. English language categorizes these phonemes into two main types: *vowels* and *consonants*.
+
+> [!Note]
+>
+> The phonetic notation system employed in this tutorial is the D.J. Phonetic transcription, introduced by [Daniel Jones](https://en.wikipedia.org/wiki/Daniel_Jones_(phonetician)) who published his *English Pronouncing Dictionary* (EPD) back in 1917 and continually revised it over many years. Eventually handed over to Cambridge University Press, its name was revamped as the [*Cambridge English Pronouncing Dictionary*](https://dictionary.cambridge.org/pronunciation/english/dictionary) (CEPD). The CEPD rolled out its 15^th^ edition sometime around 1997 with an additional set of symbols for American pronunciations tallied along. Now on par with their [18^th^](https://www.cambridge.org/gb/cambridgeenglish/catalog/dictionaries/cambridge-english-pronouncing-dictionary-18th-edition) outing, this sitely respin of Jone's original framework has been widely adopted amongst major authoritative dictionaries - including but not limited to [Oxford](https://dictionary.cambridge.org/pronunciation/english/dictionary)'s upstanding series or [*Longman Dictionary of Contemporary English*](https://www.ldoceonline.com/) down till [*Collins COBUILD*](https://www.collinsdictionary.com/dictionary/english).
+
+### 2.1 Vowels
+
+English approximately has *20* vowels. 
+
+Vowels can be classified into *long* and *short* vowels, or alternatively, they can also be grouped as *monophthongs* and *diphthongs*.
+
+| Monophthongs |                                   | Diphthongs                                |
+| ----- | --------------------------------- | ---------------------------------------------- |
+| Short vowels | `ʌ`, `e`, `ə`, `ɪ`, `ʊ`, `ɒ`     |                                                |
+| Long vowels | `ɑː`, `æ`, `əː`, `iː`, `uː`, `ɔː` | `aɪ`, `eɪ`, `ɔɪ`, `aʊ`, `oʊ`, `eə`, `ɪə`, `ʊə` |
+
+English may well be the language with the most regional accents on Earth, leading to frequent debate over the actual number of vowel sounds. Take American English for instance, `ʌ` is pronounced as `ə`, effectively reducing one vowel sound compared to British English. Additionally, some linguists argue that `eə`, `ɪə`, and `ʊə` shouldn't count as independent diphthongs but *rhotic* versions of existing vowels:  `e`,  `ɪ` and `ʊ`, thus stripping off three more distinct vowels...
+
+A prominent feature of American English is the rhotacized `ə`. The IPA developed two specific marks to note this, with `ɚ` corresponding to `əʳ`, and `ɝ`  to `əːʳ`. Bear in mind not all instances of `ə` will be subjected to rhotacization; certain words like *focus* retain their original pronunciations as `/ˈfoʊkǝs/` rather than veering towards a rendition such as `/ˈfoʊkɚs/`.
+