There are several ways to form questions in English.
Move Helping Verb to Beginning
We can move the helping verb to the beginning of the sentence to form a basic question.
- He is playing video games.
- Is he playing video games?
Move Modal Verbs to Beginning
We can also move the modal verb to the beginning of the sentence to form a question.
- She will travel to Europe.
- Will she travel to Europe?
If the sentence does not have a helping verb, we add the helping 'do' in the appropriate form ('did' for the past tense, and 'does' for the third person singular) at the beginning of the sentence.
- He drives a car.
- Does he drive a car?
- He drove a car.
- Did he drive a car?
Question words are words such as 'what, why, where, when, who, which, how' that are used to make open-ended questions.
To form a question with a question word, put a helping verb after it: question word + helping verb.
- Who did you go with?
- Which car will you drive today?
Note that the helping verb is unnecessary when the question word is the subject of the sentence.
- Who came here? (= 'Who' is the subject → no helping verb)
- Which car is yours? (= 'Which car' is the subject → no helping verb)