Unit 21: When and if
Unfinished conditional sentences
Select a unit
- 1 Go beyond intermediate with our new video course
- 2 Reported speech in 90 seconds!
- 3 If or whether?
- 4 5 ways to use 'would'
- 5 Let and allow
- 6 Passive voice
- 7 Unless
- 8 Mixed conditionals
- 9 The zero article - in 90 seconds
- 10 The indefinite article - in 90 seconds
- 11 The. That's right - the! Learn all about it in 90 seconds
- 12 The continuous passive
- 13 Future perfect
- 14 Need + verb-ing
- 15 Have something done
- 16 Wish
- 17 Word stress
- 18 Different ways of saying 'if'
- 19 Passive reporting structures
- 20 The subjunctive
- 21 When and if
- 22 Inversion
- 23 Phrasal verbs
- 24 The future
- 25 Modals in the past
- 26 Narrative tenses
- 27 Phrasal verb myths
- 28 Conditionals review
- 29 Used to - review
- 30 Linking words of contrast
When and if
The main difference is to do with certainty. Compare these:
1) If the coin lands on tails, I'll eat these sweets.
2) When the coin stops, I'll know what to do.
In the first sentence, we don't know what will happen. The coin could land on heads or tails. Both consequences are possible, so we use if.
But in the second sentence, we are certain that the coin will stop. It's a question of when it stops, not if it stops.