First conditional
If the students don’t study, they (fail) their exams.
will fail
I (could / had to) speak English when I was 7.
could
They learned (to swim / swimming) when they very young.
to swim
Did you see the thief (who / which) stole the money?
who
My sister and I (not have) lunch yesterday.
didn't have
If you (plant) some trees, birds will come to your garden.
plant
I (could / had to) wear a uniform when I was at school.
had to
Do you enjoy to (go / going) on school trips?
going
The village (where / that) we live is far from London.
where
They never (climb) mountains.
have never climbed
If they cut down the trees in our park, we (be) sad.
will be
We (mustn't / don't have to) wake up early on Sundays.
don't have to
I can’t stand (to see / seeing) rubbish in the street.
seeing
The detective saw the fingerprints (which / where) were on the door.
which
We (have) breakfast at the moment.
are having
If she (not have) a lot of work, she will go to the forest clean-up.
doesn't have
He (can / could) run faster when he was a child, but now he is not good at sports.
could
Why did you decide (to move / moving) to London?
to move
The newspaper had a photo of the man (that / which) committed the crime.
that
Every morning she (do) yoga for 30 minutes.
does
If he (find) your keys, he will tell you immediately.
finds
We (had to/ must) do a project at school last week.
had to
We don’t mind (to get up / getting up) early when the weather is good.
getting up
We saw the castle (which / where) they made the film.
where
I (not finish) doing my homework yet.
haven't finished