Ming from Agents of Speech explains why kids struggle to describe their day. Some children can only answer in single sentences, not longer stories, and parents asking too many follow-up questions makes it worse. It's like being asked to speak in a foreign language.
Chapters
The second point is, are you jumping through a lot of steps? Like, have you been jumping a lot of steps and thinking about why my child won't recall what happened at school? The thing is, can they even recount a story that they learned before? Are they able to tell a story? Are they able to tell you how to play a game? Are they able to do these things? If your child is stuck at one sentence per utterance, meaning every time they say one sentence at a time, they can't even do multiple utterances. So even if they did understand the concept of like, how was your day? The then and there and the when questions, can they even speak in a way that would make it so that you don't have so many follow up questions and annoy the heck out of them? Right? So that happens to me when I have to speak in a foreign language. Like, they asked me, oh, how was whatever? And I was like, I'm going to say one sentence or one word and they're going to keep on saying something, so I'm going to pretend I don't know.