Asking if somebody had a good day

Question

On arriving from school does it make any sense asking the kid You had a good day? How does that sound to you?

Answer 1

"You had a good day?" is okay. It is a question that is not using the normal form of a question, though. So it's basically making a statement and asking for confirmation, similar to "You had a good day, right?". This makes sense if you already have some reason to assume that their day was good. For example, you could say it if they come inside laughing and smiling.

The more standard way to ask would be:

Did you have a good day?

The first word or two of this can be omitted in informal contexts (like a child coming home from school). Using have vs. had is the important difference. It's a bit confusing because it looks so much like the original version with had, but the meaning is just the same as the "Did you have a good day?" version:

You have a good day?

Have a good day?

Another more open ended option is:

How was your day?