I like his childish innocence.
His childish habits were disliked by us.
He is known for his childish acts.
This is not a childish affair.
It is a childish thing to do.
He can be very childish at times.
Why do you indulge in such childish behaviour?
The childish behavior of you is self evident.
What a silly childish comment!
It is childish on your part.
He was ridiculed for his childish acts.