Indirect questions

An indirect question wraps a question inside a polite opener ('Could you tell me…', 'Do you know…') or inside a statement ('I'm not sure…', 'I wonder…'). The information you want is identical; only the packaging changes, and with it the level of politeness.

English speakers reach for indirect questions whenever directness might sound abrupt — approaching strangers, making requests at work, or querying an official. Because they bury one clause inside another, they also count as complex sentences, which is exactly why they matter for the IELTS Grammatical Range criterion.

• Could you tell me where the station is?(embedded clause in statement order)
• Could you tell me where is the station?(→ where the station is)
• Do you know how long the delay will be?(polite opener + embedded question)

Inside the embedded clause, the question flips back into statement order: subject before verb. The auxiliary do/does/did disappears completely, and its tense marker returns to the main verb — 'Where does she work?' becomes 'Do you know where she works?', and 'When did they leave?' becomes 'I'd like to know when they left.'

With the verb be there is no auxiliary to delete; be simply steps back behind its subject: 'Why is the office closed?' becomes 'Can you explain why the office is closed?' This tiny repositioning is the single most common slip, because the direct-question order is so automatic.

• I'd like to know when the results come out.(do deleted — plain statement order follows)
• Can you explain why is the printer offline?(→ why the printer is offline)
• Nobody told us how much the visa costs.(does disappears and cost regains its -s)

A yes/no question has no question word, so English inserts if or whether to hold its place: 'Is the museum open?' becomes 'Do you know if the museum is open?' In everyday speech, if and whether are interchangeable in this slot.

Whether is the only choice in three places: directly before 'or not', after a preposition, and before a to-infinitive. In formal writing, whether is generally the safer and more elegant pick.

• I'm not sure whether the landlord received my message.
• Everything depends on whether the sponsors sign the contract.(after a preposition, only whether works)
• She can't decide if to accept the offer.(→ whether to accept — before a to-infinitive, use whether)

The opener decides the punctuation. If the frame is itself a question — Could you tell me…?, Do you know…?, Do you happen to know…? — the whole sentence ends with a question mark. If the frame is a statement — I wonder…, I'm not sure…, I'd like to know…, I have no idea… — it ends with a full stop, even though a question hides inside.

Openers also carry register. 'Do you know…?' is neutral; 'Could you tell me…?' is polite; 'I was wondering if you could…' is the softest of all and doubles as a request form in emails and formal letters.

• Do you happen to know whose umbrella this is?(question opener → question mark)
• I wonder who designed this building.(statement opener → full stop)
• I'd like to know why the invoice was rejected?(statement opener → full stop, not a question mark)

An ordinary indirect question keeps its original tense, because you are asking now: 'Could you tell me where the lift is?' Reported questions are different: when you report what somebody asked in the past, the reporting verb is past ('asked', 'wanted to know') and the tense inside usually shifts back one step.

Both structures share the same statement word order, so mastering one gives you the other almost for free. The only extra machinery in reported questions is backshift and pronoun changes.

• The examiner asked me what I did at weekends.(backshift: do → did)
• The border officer wanted to know how long we were planning to stay.
• She asked me where do I work.(→ where I worked — statement order plus backshift)