The tone changes rules for “一” （“一”的变调） The - Cchatty

The tone changes rules for “一”
（“一”的变调）

The basic tone of the numeral “一” is the 1st tone. when read alone, or in counting or calling out numbers, its basic tone is used.

The tone of “一” may vary with the tones of the syllable that comes after it: if preceded by the 1st, 2nd, or the 3rd tones, “一” is pronounced as the 4th tone; if it is preceded by a 4th tone, it is pronounced as the 2nd tone, eg:

“一” + 1st tone：
一些, yì xiē (some; a few; a little)
一般, yì bān (same; ordinary common; general)
一边, yì biān (one side; either side doing while)


“一” + 2nd tone：
一直, yì zhí (continuously; always)
一同, yì tóng (together)
一旁, yì páng (at the side)

“一” + 3rd tone：
一起, yìqǐ (together; with altogether)
一点儿, yì diǎnr (a bit; a little)
一本(书), yì běn shū, (a book)

“一” + 4th tone：
一遍, yí biàn (once through one time)
一个, yí gè (a; an; the)
一切, yíqiè (everything; every all)
一样, yíyàng (same; like)
一下儿, yí xiàr (give it a go; once one time; do for a bit)
一旦, yí dàn (once; in case; if)
一定, yí dìng (surely; certainly)
一会儿, yí huìr (a moment; a while)
一半, yí bàn (a half)
一路,yí lù (the whole journey; all the way)
一共, yí gòng (altogether; total)