The first conditional talks about the result of a possible future event. The present simple tense is used in the if-clause, and the future simple tense used in the main clause.
- If I see her, I’ll tell her.
(if-clause/possible future event/present simple/see – main clause/result/future simple/will tell)
- If you cook the dinner, I’ll wash the dishes.
(possible future event/cook – result/will wash)
- She’ll be late if the train is delayed.
(will be late – delayed)