Conditionals

A conditional sentence has two parts: an ⟦if⟧ part (the condition) and a main part (the result). There are four main types. Which one you use depends on whether the situation is always true, possible in the future, imaginary now, or imaginary in the past.

Key facts

  • Zero (always true): ⟦if⟧ + present, present. ⟦If you heat ice, it melts.⟧
  • First (a real possibility): ⟦if⟧ + present, ⟦will⟧ + verb. ⟦If it rains, we will play inside.⟧ Never ⟦will⟧ in the ⟦if⟧ part.
  • Second (imaginary or unlikely): ⟦if⟧ + past, ⟦would⟧ + verb. ⟦If I had wings, I would fly.⟧ For advice: ⟦If I were you, I would ask.⟧
  • Third (an imaginary past: it didn't happen): ⟦if⟧ + ⟦had⟧ + past participle, ⟦would have⟧ + past participle. ⟦If she had left early, she would have caught the bus.⟧
  • The ⟦if⟧ part can come first (with a comma) or second (no comma): ⟦We will play inside if it rains.⟧

Worked examples

Example 1

Complete: ⟦If you ___ (mix) blue and yellow, you make green.⟧

  1. It is always true, so both parts are in the present.
  2. ⟦If you mix blue and yellow, you make green.⟧

Answer: ⟦mix⟧

Example 2

Complete: ⟦If Omar studies, he ___ (pass) the test.⟧

  1. The ⟦if⟧ part is in the present and it is a real possibility.
  2. The main part takes ⟦will⟧ + verb: ⟦he will pass the test⟧.

Answer: ⟦will pass⟧

Example 3

Which type is this? ⟦If we had left the window open, the cat would have escaped.⟧

  1. ⟦had left⟧ and ⟦would have escaped⟧: ⟦had⟧ + past participle, ⟦would have⟧ + past participle.
  2. It is about an imaginary past (the window was closed): the third conditional.

Answer: third conditional