台語（台灣話）又稱為台灣閩南語，屬於漢語族 閩語支 閩南語 的泉漳片，其發音與福建廈門話、漳州話最為接近。
Taiwanese (also referred to as Taiwanese Hokkien or Taiwanese Minnan) is generally similar to the speech of Quanzhou (泉州), zhangzhou (漳州), and Amoy (廈門),
台灣話與其他漢語系語言同為聲調語言，聲調在語句中有辨義作用，且有相當繁複的變調規則。傳統聲調名稱，分平、上、去、入四聲，四聲又各分陰、陽，共八個聲調。現代標準漢語（即國語或普通話）入聲調消失併入其他三聲，且上、去兩聲不分陰陽。今閩南語泉州話、台灣鹿港腔完整地保留了傳統的八聲；而台灣通行腔、廈門話、漳州話、同安話只保留了七個聲調，將陽上聲混入陰上聲或陽去聲，因此基本上台灣通行的通行腔只有七個聲調。
Taiwanese is a tonal language (聲調語言) with extensive tone sandhi rules (變調規則). In the traditional analysis, there are eight "tones", numbered from 1 to 8. Strictly speaking, there are only five tonal contours. But as in other Chinese varieties, the two kinds of stopped syllables (入聲) are considered also to be tones and assigned numbers 4 and 8. In Taiwanese tones 2 and 6 are the same, and thus duplicated in the count.
The following table, which is quoted from English Wikipedia, and originally from Soli Wu's Mandarin-Taiwanese Comparative Living Dictionary (吳守禮 編著之 國臺對照活用辭典), shows the eight tones in Taiwanese (note: the 2nd tone sounds exactly like the 6th tone) as well as the slight difference between Taipei speech and Tainan speech -- 下表標註各聲調的調值，並顯示台北腔與台南腔略有不同：
第一聲（陰平）語調上揚聲高，屬於高平音；第二聲（陰上）語調重短氣下，屬於高降音；第三聲（陰去）語調低下氣收，屬於下突音；第四聲（陰入）語調平出氣穩，屬於低促音；第五聲（陽平）語調低粘回升，屬於迴旋音；第六聲（陽上）語調低平［註：指台灣老鹿港腔而言，調值為 (22)，至於台灣優勢腔，無論偏泉腔或偏漳腔，都與第二聲相同，亦即上聲不分陰陽］；第七聲（陽去）語調中轉基平，屬於基調音；第八聲（陽入）語調促短急切，屬於高促音。
Examples of the tones of Taiwanese: 衫 saⁿ, 短 té, 褲 khò͘, 闊 khoah, 人 lâng, 矮 é, 鼻 phīⁿ, 直 ti̍t. (Note: Tone sandhi rules do not apply in this sentence.)
The 1st tone (e.g. 衫, 獅, 君, 番) is read as high as (55) or (44).
The 2nd tone (e.g. 短, 虎, 滾, 反) is read as falling (51) or high falling (53).
The 3rd tone (e.g. 褲, 豹, 棍, 販) is read as low falling (31) or (21) or just low (11).
The 4th tone (e.g. 闊, 鱉, 骨, 法) is read as mid stopped (32) or (3ʔ) or lower stopped (21) or (2ʔ).
The 5th tone (e.g. 人, 猴, 裙, 煩) is read as rising (14) or (24) or (25).
The 6th tone (e.g. 矮, 狗, 滾, 反) is read by most Taiwanese people in the same way as the 2nd tone.
The 7th tone (e.g. 鼻, 象, 郡, 犯) is read as mid-pitched (33).
The 8th tone (e.g. 直, 鹿, 滑, 罰) is read as high stopped (4ʔ) or (5ʔ).
下圖（取自 Wikipedia）為台語八聲調之圖示：在台灣，大部分地區第六聲調與第二聲調類同，只在部分地區如鹿港等地仍保有原第六聲調 -- See the following diagram, which shows the Taiwanese tones, close to Taipei values:
在探討如何「變調」之前，先要知道，在什麼情況下應唸本調；換言之，應唸本調（而不變調）的字----或該字在「語句／語詞」中的位置----有下列三種，不受「變調規則」影響。 The following syllables are unaffected by tone sandhi:
- The final syllable in a sentence, noun (including single syllable nouns, but not pronouns), number, time phrase (i.e. today, tomorrow, etc.), spatial preposition (i.e. on, under), or question word (i.e. who, what, how) [Note: I don't think we have "spatial prepositions" in Taiwanese, but we do have "spatial postpositions", e.g. [山] 頂, [崁] 下 or 腳, [市] 內, etc.]
- The syllable immediately preceding the possessive particle 的 (ê) or a neutralized tone. In POJ, this is the syllable before a double hyphen, e.g., 王先生 (Ông--sian-siⁿ)
- Some common aspect markers: 了 (liáu), 好 (hó), 完 (oân), 煞 (soah)
台語的變調規則，可從上面的「連續變調示意圖」得到化繁為簡的初步理解。例如：第一聲變調後說 (唸) 成第七聲；第七聲變調後說 (唸) 成第三聲；第三聲變調後說 (唸) 成第二聲；第二聲則有兩種情形，偏泉腔變成第五聲，而偏漳腔變成第一聲；至於第五聲，偏泉腔會變成第三聲，而偏漳腔會變成第七聲。
這裡所說的「非入聲字」的變調規則，除了依上圖所示，可以理出一些頭緒，也可從我所繪製的這張圖 (see below) 得到一目瞭然的「直覺式／聲調圖像化」的理解：
- If the original tone number is 1, pronounce it as tone number 7.
(e.g. the first 燒 in the phrase "燒燒"). - If the original tone number is 7, pronounce it as tone number 3.
(e.g. the first 老 in the phrase "老老") - If the original tone number is 3, pronounce it as tone number 2.
(e.g. the first 笑 in the phrase "笑笑") - If the original tone number is 2, pronounce it as tone number 1 (Zhangzhou/Tainan speech) or 5 (Quanzhou/Taipei speech).
(e.g. the first 冷 in the phrase "冷冷") - If the original tone number is 5, pronounce it as tone number 7 (Zhangzhou/Tainan speech) or 3 (Quanzhou/Taipei speech).
(e.g. the first 紅 in the phrase "紅紅")
For these rules and the examples, see the chart (diagram) that I've made and posted above.
And there are some more rules and examples as follows:
- If the original tone number is 4 and the final consonant is not h (that is, it is p, t, or k), pronounce it as tone number 8.
(e.g. the first 澀 in the phrase "澀澀" ) - If the original tone number is 8 and the final consonant is not h (that is, it is p, t, or k), pronounce it as tone number 4.
(e.g. the first 直 in the phrase "直直") - If the original tone number is 4 and the final consonant is h, pronounce it as tone number 2.
(e.g. the first 拍 in the phrase "拍拍") - If the original tone number is 8 and the final consonant is h, pronounce it as tone number 3.
(e.g. the first 熱 in the phrase "熱熱")
上面所提及的「燒燒／老老／笑笑／冷冷／紅紅」等語詞，是一些「非入聲字」的變調實例；而「澀澀／直直／拍拍／熱熱」等，則屬於「入聲字」的變調實例了。請參閱下圖。 (For the tone sandhi rules of tones 4 and 8, see the chart below)：
The additional rules can be classified as "double tone sandhi", "triple tone sandhi", "tone sandhi before the suffix á (仔)", etc. For more information about Taiwanese tone sandhi, you and I can easily look it up in Chinese Wikipedia and English Wikipedia; of course, we can find and read many more professional articles on other websites, as well.
關於台語的聲調變化，還有許多細節，有待研究探討；本文僅針對台語的「基本聲調」及台灣優勢腔的「變調規則」做一番整理，提供讀者諸君參考。歡迎不吝指教。（全文完）
