Dear teachers
"When did you see her?"
"When have you seen her"?
Does this expressions have the same meaning and can they both be used indifferently?
Thanks
Guillaume
No, they are not interchangeable.
In the first question, 'when' means specifically 'at which time in the past?', and implies expectation of an answer involving a definite past time adverbial such as 'last week/yesterday/in 1993', whereas in the second it means rather 'at what
sort of time?', referring, not to a uniquely
past time, but to a
cyclically recurrent one (such as 'whenever the weather is good/in the spring, when the daffodils are out', etc.), i.e. one capable of occurring again at some point in the future.
Thus, for example, the question "When have you been to London?" - in addition to possibly indicating doubt on the part of the speaker as to whether the addressee has ever actually performed the act in question - could quite legitimately elicit an answer such as "Every time I've had to take a party of sightseers to Buckingham Palace!", i.e. one naturally entailing the possibility that the speaker may well engage in this action again at some future time.