Do you confuse with If-clause (1)

The clause after if, we usually talk about uncertain events and situations: things which may or may not happen/ be true. An if-clause oftern refers to a condition--something which must happen so that something else can happen.

There are three special structures named 'first', 'second' and 'third' conditionals.

First conditional         If + present                     will + infinitive
                                If we play tennis                      I’ll win
Second conditional If + past                              would + infinitive
                                 If we played tennis               I would win
Third conditional        If + past perfect                  would have + past participle
                                If we had played tennis                I would have won

However, if-clause also has ordinary structures.
    (1) The same tenses as with other conjunctions
          When we are not talking about 'unreal' situations, we use the same tenses with if as with other conjunctions. Present tenses are used to refer to the present, past tenses to the past.
          Oil floats if you pour it on water.
          If John didn't come to work yesterday, he was probably ill.
     (2) present tense with future meaning
          We normally use a present tense to talk about the future.
          I'll give him your love if I see her.