Fergie had to feature her son on her new album after hearing him speak French.

The 'Big Girls Don't Cry' hitmaker was amazed when her four-year-old son Axl repeated some little French phrases that she said so she recorded them and put them in her music.

She told The Today Show: ''He sings songs all around the house so I brought this demo [for the song] home and I was just playing it, listening to it and I'm saying, like, 'Enchante, comment allez-vous, tres bien', and then he goes [mimicking her], 'Enchante, comment allez-vous...' and I go, 'Oh my gosh!'

''When you hear your kid singing, in French, it was just mummy pride. I had to just record it.''

And the 42-year-old singer loved having Axl - who she shares with her estranged husband Josh Duhamel - join her on set when she was making a video for 'A Little Work'.

Speaking about his cameo, she shared previously: ''It was just really natural. We had planned to just film it whether he wanted to come or not - I just missed my son and wanted him to come to set! I was like, 'Well, we can walk out of the church with him or not, depending on what mood Axl is in. If he's crying and he doesn't want to do it, then we wont do it!'

''But he was completely into it, we just made it like a play date. We play all the time at home in several costumes per day, so for us it was just another activity. We have a lot of good times!''