If clause (conditional sentence)
1.1 If S + V1, S + will + V1
If we add 1 and 2, we will get 3.
If I get up late, I will miss the class.
1.2 If S + V, S + V1
If we study hard, we pass EN111.
2. Present unreal
If I were a bird, I would fly.
If S+ V2, S + would + V1
If I came here yesterday, I would understand the lesson.
3. Past Unreal
If S + had + V3, S would have V3.
If I had joined the party last night, I would have met previous sparkling love.