The conversation between human and AI assistant.
[|Human|] Rewrite the following sentence so that it is grammatically correct: 
"Peter and I went shopping yesterday, but I wasn't sure if he is was enjoying himself"
[|AI|] "Peter and I went shopping yesterday, but I wasn't sure if he was enjoying himself."
[|Human|] 
Rewrite the following sentence so that it is grammatically correct: 
"Peter and I went shopping yesterday, but I wasn't sure if he is was enjoying himself"