primary question of english

Do you mean "True" or "Correct"?

All 4 sentences are true and correct.

I have some questions and I have questions both means 我有問題

When you tell someone "the dogs are coming", you are referring to those dogs both of you know. "The dogs" refers to some specific dogs.

When you say "dogs are coming", it means some random dogs are coming towards you. It could be any stray dogs

I have some equestions.
The dogs are coming.