Does he respond to you when you call his name'?
If he does, then it's ok.
Keep telling, show examples, etc.
You can use pictures of your child, point to it and as 'who is he?'
One day he will know how to answer. Be patient, many children at this age still can't say his own name yet.
Well, my girl can say things like her name and should be able to answer interview questions (like colors, name pictures etc) but she can only say it to people whom she likes or she's familiar with (she will keep quiet...very quiet).
She is a friendly type but needs to take some time to 'warm up' to strangers.
I am just going to send her to a school with no interviews