Hi Samuel. Let's start with some examples:
Yes/No questions - Are you a painter? Is he a nice guy? Have you been there before? Do you know Jane?
Object questions - What do you do? How does he do it? How much does it cost? Where is the post office?
Subject questions - Who invented the telephone? What is the capital of London? Who took my pen?
Yes/No questions - Yes, these all have an auxiliary (helping) verb before the pronoun/subject. Note that these are all formed by switching the subject and verb in a regular statement (e.g. 'He is a doctor' -> 'Is he a doctor?'). If there is only a main verb in the statement, then we use the verb 'do' to form the question (e.g. 'She wants more homework'-> 'Does she want more homework?').
Object questions - these take the form: Question word -> auxiliary (helping) verb -> subject -> main verb
So actually, the main verb comes after the subject, but helping verbs (e.g. 'do', 'are', 'have') come before it.
Subject questions - the question word is the subject and comes at the start of the sentence.
Hope this helps!