Dido had to "practise heavily" to stop herself swearing so much.
The 'Thank You' hitmaker - who has seven-year-old son Stanley with husband Rohan Gavin - admitted she used to curse a lot but thought she ought to reign in the bad language when she became a parent.
Asked her favourite swear word, she said: "It's probably 'shirt without the R' as my son Stanley once said. He was like, 'Why are you saying shirt without the R?'
"I practised heavily at containing my swearing when I was pregnant.
"I think I've done a pretty good job, I used to be pretty free with it.
"The best one I had was I was singing 'White Flag' and I got to the chorus and Stanley said, 'Mummy, bad word.' I was like, 'What are you talking about?' Then I realised the lyric was, 'I will go down with this ship' and he'd misheard it the whole time.
"Maybe that's why it did so well, everyone misheard it."
The 47-year-old singer loves being a parent and finds hanging out with her son "very relaxing" - though he can be "quite brutal" about her singing.
She told Q magazine: "Having a seven year old is the most fun you're gonna have.
"It takes your mind off stuff. I like hanging out with him and we do fun stuff.
"There's something very relaxing about it. You're not thinking about work or anything, you're just having really bizarre conversations and he's really into music.
"He loves it when I sing my songs, but he's not so keen when I start singing other people's songs.
"He holds his hands over his ears. It's quite brutal, to be honest."
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