I can't sing.

我不会唱歌。

《柯林斯英汉双解大词典》

You may be thinking, 'But you don't understand. I can't sing.

你可能会想：“你根本就不会理解，我不想唱了。”

youdao

You may be thinking, 'But you don't understand. I can't sing.'

你可能会想：“你根本就不会理解，我不想唱了。”

youdao

'I Puritani' I like a little bit less, probably because I can't sleep at night before I have to sing it.

WSJ: Joseph Calleja | Faust | Here to Deal With the Devil | Cultural Conversation by Barrymore Laurence Scherer

Except you don't sing messed up, you sing something else which I can't say on National Public Radio.

NPR: Thom Yorke's 'Eraser' Prompts a Letter

"I can't sing, but I used to sing with Whitney, just for fun, " he said.

BBC: Whitney Houston