I have seen my DD occasionally regress by over regularising verbs in written text. It freaked me out a bit until DW, a high school teacher pointed out that this is common before a growth spurt or developmental milestone is attained.

I stopped worrying and things did self correct. My DD occasionally reverts back to reading How To Tame Your Dragon and Gerenimo Stilton books so I wouldn't pay undue attention to this. He will be over it soon enough I expect.

Become what you are