First Conditional [If]:

Usage:
Think of the First Conditional as the "Real Possibility" sentence. We use it to talk about events that will probably happen in the future. If the condition is met, the result is very likely to occur.

The Structure:

  • If Clause (The Condition): If + subject + present simple
  • Main Clause (The Result): subject + will ('ll) / won't + base verb

  • Extra Example: If it rains tomorrow, we will cancel the picnic.
  • Extra Example: She will pass the exam if she studies hard.

2. Second Conditional [If]:

Usage:
Think of the Second Conditional as the "Daydream" or "Imaginary" sentence. We use it to talk about events we can imagine, but they probably won't happen. It's often used for hypothetical or impossible situations in the present or future.

The Structure:

  • If Clause (The Condition): If + subject + past simple
  • Main Clause (The Result): subject + would ('d) / wouldn't + base verb

  • Extra Example: If I won the lottery, I would buy a private island.
  • Extra Example: I would travel the world if I had more free time.

Important Note:
If the sentence starts with the "If" clause, we must put a comma (,) between the two clauses. If the main clause comes first, no comma is needed.