The differences between WILL and WOULD. The easiest way to identify the differences between these two modal verbs is by looking at the rules below.

Thanks to Dhanesh S for requesting this lesson.

When to use WILL:

Rule #1: To talk about future ‘facts’ (remember it may only be a fact from the speaker’s point of view)

• The sun will rise at 6.23am tomorrow.
• I will always remember my first day at school.

Rule #2: To create first conditional sentences

• If you eat too much, you will get fat.
• You will pass the exam if you study hard all week.

Rule #3: To ask people to do something (more informal/less polite than using ‘would’)

• Will you pass me the a pencil?
• Will you tell your father that dinner’s ready?

Rule #4: To express a present belief

• John left for the airport hours ago. He will be flying by now.

When to use WOULD:

Rule #1: As a past tense of WILL for a future fact

• I hope he will pass his exam / I hoped he would pass his exam.

Rule #2: To talk about an imaginary / unreal situation.

• She would look good with a better haircut.

Rule #3: To create second and third conditional sentences

• He would look good if he had a better haircut. (second conditonal)
• He would have passed his test if had studied, but he didn’t put the work in. (third conditional)

Rule #4: To talk about past habits

• When I was a kid, I would spend every weekend playing football with my friends.
• I would sit at the kitchen table to do my homework every night.

Rule #5: To make polite requests and offers

• Would you like a cup of coffee?
• It’s a little cold – would you mind closing the window?

Rule #6: In reported speech

• Jane: I won’t be going to the party. > Jane said she wouldn’t be going to the party.

Rule #7: To estimate something

• I would guess he’s around 50? He’s not old, but he has some grey hair.
• I would say it’s about 20 kilometres from here, more or less.

Rule #8: To talk about something that refused to happen in the past

• I tried to get in but the door wouldn’t open.
• He had terrible toothache but he wouldn’t go to the dentist.