Indirect interrogatives
V + wh-clause – Ask where the station is
The verbs ask, wonder, doubt, enquire, don’t know control indirect interrogatives. The subordinator if is often used as an alternative to whether in indirect questions where the answer is either yes or no:
We asked what we should do/what to do.
The tourist enquired why the museum was closed.
Pat wondered whether/if her friends would recognize her.
As indirect interrogatives contain an embedded question, it is important to remember that subject–operator inversion does not normally occur in embedded questions, unlike the obligatory inversion found in most independent interrogatives. Compare:
independent interrogative dependent interrogative
Where is the dining-car? Let’s enquire where the dining-car is.
Not *Let’s enquire where is the dining-car.
