WHETHER - IF
When to use 'whether' and 'if' in English. 'Whether' and 'if' are used as follows : To express alternatives : I don't know whether/if I'll go to the party on Saturday (or not). To report a question : Are you going to the party? - She asked me whether/if I was going to the party (or not). Only whether can be used in the following cases: When followed by an infinitive : I don't know whether to go to the party or not. After prepositions : It depends on whether I get home early or not. When whether begins a clause which is the subject of a sentence. Whether I go to the party or to the cinema makes no difference to me. When followed directly by 'or not' I'll be happy whether or not I go to the party.