You should study the grammar point "questions and negations" http://learnenglish.britishcouncil.org/en/english-grammar/clause-phrase-and-sentence/verb-patterns/verbs-questions-and-negatives
In a nutshell:
1 "Normal verbs" need a form of to do (do, does did - don't, doesn't, didn't) in questions and negations.
2 All verbs are "normal verbs", except some "particular verbs". Particular verbs are
2.1 The verb to be
2.2 Auxiliary verbs used for the formation of tenses (will for future, would for conditional tense/mood, have/has/had for the perfect tenses).
2.3 Modal verbs: can/could, may/might, must/---, shall/should, will/would
2.4 "to have" is a special case. It is a particular verb when used for the perfect tenses, and a normal verb when meaning to possess and similar ideas.
There is one special rule: questions with who/what/which+noun, subject case, never use to do for questions or negations.
I have given the essentials of this grammar point. For details see a grammar.
As to your question why English uses to do in questions and negations, though most languages don't need such a special marker, that is a question about which I have never read anything though the question is a good one.
I have a personal theory and I have presented it here somewhere on stackechange. When I find it I'll add the link.
Added: What have native speakers in their mind when they use "to do"?
@GamalThomas - Good question, but not so easy to answer if you don't have such a verb. Have a look at various online dictionaries such as Oald, The Free Dictionary, Collins, MacMillan, and look up the word in dictionaries of your own tongue. It would be good to know your mother tongue. If you do the cooking or shopping you perform the necessary actions for this job. It is a general verb; I call such words chewing gum words, you can use them for a lot of things. To do can be placed before a verb for an emphasizing effect, eg I do hate this teacher. And as we have seen it is a marker for questions and negations. Don't know whether all this helps you much.