bedroom – wah-shi
Written as wòshi or woshi
To remember that bedroom is pronounced wah-shi (woshi) in Mandarin Chinese, use the following mnemonic:
There were dirty clothes all over his bedroom, so his mum told him to do some washing (wah-shi).

Tones
Wah (washing) is a 4th tone with \ as an accent.
Associate washing, a 4th tone, with lowering things like trip or slide down. See Tones and Mnemonics.

I tripped over and dropped all of the clean washing.
Remember
Wah = 4th tone = \