To form yes/no questions where there is an auxiliary verb or a modal verb, we invert the word order of a positive sentence.
Review of question forms
To form yes/no questions where there is an auxiliary verb or a modal verb, we invert the word order of a positive sentence. (He is a teacher > Is he a teacher?)
When there is no auxiliary verb we use ‘do’ to form the question.
With question words
The same rules apply when there is a question word (‘what’, ‘where’, ‘when’, ‘why’, ‘who’, ‘which’, ‘how’, ‘how much’, ‘how many’)
Where there is an auxiliary or modal verb, that verb is used to form the question.
Where there is no auxiliary verb, we use do.
Sometimes you might see questions like this.
There is no auxiliary verb and the word order is not inverted.
These are called subject questions – because the question word is the subject of the sentence.
Look at these two questions.
In the first question, Romeo is the subject of the verb.
In the second question ‘who’ is the subject and Romeo is the object.