1
× Could you tell me what is the time?
√ Could you tell me what the time is?
× Do you know where is Oxford Street?
√ Do you know where Oxford Street is?
In questions starting with “Do you know …”, “Could you tell me …”, “Do you have any idea of …”, etc, and followed by a wh- word (what/how/where, etc) there is an inversion of subject and verb (as in any question), but the verb after the wh- word is not inverted, because the main verb of the sentence is the verb before the wh- word. We say, “What is the time?” or “Can you tell me what the time is?”
2
× I don’t know how much does it cost.
√ I don’t know how much it costs.
× I’d like to know where were they going.
√ I’d like to know where they were going.
The sentences above are indirect questions. In indirect questions, we do not put auxiliary verbs before the subject; there is normally no subject-verb inversion: ‘Please, tell me why we are still waiting.’ ‘I’m wondering where the postman may be.’