I can read, speak and write Chinese.

For the rest of your input, you may be right with kindergarten students. On the other hand, these points are standard topics in training to teach; not all students of ESL are at kindergarten level.

Else, 说中文吗？Then- you can explain grammar to them better. I don't see a 5 year old Chinese comprehending an english explanation about grammar. It'd be more effective for them to hear it in Chinese.