chair – ee-zer
Written as yǐzi or yizi
To remember that chair is pronounced ee-zer (yizi) in Mandarin Chinese, use the following mnemonic:
"Surely there's a chair that's easier (ee-zer) to assemble".

Tones
Ee (easier) is a 3rd tone with ∪ as an accent.
Associate easier, a 3rd tone, with a horse shoe or horse or smile. See Tones and Mnemonics.

It's easier to smile than to frown.
Remember
Ee = 3rd tone = ∪