Student or Learner
What is the difference between 'if' and 'when' in mneaning or tone in the following sentences?
1. Call me (if/ when) you have time.
2. (If/ When) there is a fire, do not use this lift.
3. (If/ When) you feel unwell, call our staff for help.
1 - 'when' (if the speaker has a reasonable expectation that he'll be called eventually - 'if' would give an impreesion of despair [and would often be combined with 'ever' - 'Call me if you ever have the time; but I don't suppose you will.']}
2 -'if'' would be more appropriate if your normal expectation is that there won't be a fire. But imagine you are being introduced to a job in which fires are a frequent occurrence - say once a week. They are an occupational hazard. The person training you might say 'when there is a fire...'.
3 As in 1 and 2, it's all about expectation. 'If' is probably more likely, but 'when' is quite possible. If a hospital is administering a drug that has a know and unavoidable side effect, 'when' would be the one to use.
Last edited by BobK; 04-Dec-2010 at 14:33. Reason: Fix typoes