Example sentences
zuò坐zhè这bǎ把yǐ椅zi子。
Sit in this chair.
yǐ椅zi子huài坏le了。
The chair is broken.
About this word
椅 means chair and 子 is a noun-forming suffix, so 椅子 is just "chair" with a grammatical tag glued on. That 子 turns up all over everyday nouns: 桌子 (table), 杯子 (cup), 儿子 (son), 名字 (name). It always goes neutral, yǐ zi, never yǐ zǐ. 椅 does not stand alone in speech, so the 子 cannot be dropped. The measure word is 把: 一把椅子.
The story behind the character
椅
木 (wood) plus 奇 (sound). It was a kind of tree, the 椅 tree, and only later got borrowed for the wooden seat. So "chair" began as a tree.
子
子 is a newborn drawn from life. Big head, arms stretched out, legs swaddled together. The oldest forms are exactly that, and Xu Shen simply marked it 象形, a picture. It is also the first of the twelve earthly branches, the one paired with the rat, which is why the character shows up on old calendars and in the zodiac.