Grammar topic
Conditionals: if, unless, in case and wish
A conditional sentence links a condition to its result. The main types differ in one thing: how real or likely the condition is. Learn the types in order from zero to third, then the words that replace if, such as unless, in case and as long as.
Lessons in learning order
Each lesson explains one rule and ends with a 20-question drill.
Conditional sentences (type 1, 2 and 3)
If plus the right verb pattern: real, unreal and impossible situations, with the comma rule.
Zero conditional: facts and habits
When the result is always true, both halves of the sentence take the present simple. If and when mean the same thing here.
First conditional
If plus the present simple, will plus the base verb: a real possibility in the future.
Second conditional
If plus the past simple, would plus the base verb: the present that is not real.
Third conditional
If plus had and the past participle, would have plus the past participle: the past that cannot change.
Mixed conditionals: past and present together
When one half of a conditional looks at the past and the other at now, the sentence is mixed. The time words tell you which pattern you need.
Unless: if not, and how to use it
Unless introduces the one condition that stops something: "Unless you hurry, we will be late." The clause stays in the present simple, even about the future.
In case vs if
If says what must happen first; in case says do something now because something might happen later.
As long as, provided that and on condition that
Three formal ways to say "only if", the present simple after them, and the difference from if and unless.
Wish and if only: past, present and future regrets
Wish moves the tense one step back to show that the situation is unreal: past simple for now, past perfect for then, and would for what annoys you.