To + infinitive

How do we know when to use ‘to + infinitive’ (to know, to see, to find etc), and not the gerund or the bare infinitive?  It can be difficult to know, but we have three rules as to when we use the ‘to + infinitive’.

When to use ‘to + infinitive’

1. We use ‘to + infinitive’ after specific verbs. (ask to go, plan to find etc.).
2. We use ‘to + infinitive’ after most adjectives to give a reason. (happy, difficult etc.).
3. We use ‘to + infinitive’ to show purpose, ‘to & for’ for a full description on ‘to for purpose’.

We use ‘to + infinitive’ after specific verbs 

Want	Did they really want to jet ski?
Learn	You must learn to behave.
Plan	She’s planning to take a Spanish course.
Hope	David hopes to become an astronaut.
Decide	Don’t decide to leave so soon, please.
Help	Can you help me to solve this?
Promise	Our clients promised to make a deal with us.
Would like	He wouldn’t like to come with us.
Decide	We’ve decided to try.
Agree	Don’t agree to stay if you don’t want to.
Ask	I’m asking you to do it for me.
Would love	She’d love to join in.
Would hate	I’d hate to know.
Wait	They’ve been waiting to see their favourite actor.
Seem	The washing seems to be done.
Manage	Could you manage to make an appointment?
Offer	My employer offered me more vacation time.
Choose	You can choose to leave if you want.
Can afford	Henry can’t afford to go.
Demand	I’m demanding you to leave at once!
Prepare	Please, prepare to wait, there’s a long line.
Arrange	He’ll arrange for you to arrive at 22:00.
Deserve	James doesn’t deserve to win the lottery.
Claim	Are you claiming to be a charlatan?
Appear	My bike doesn’t appear to be working.
Intend	They intend for you to have great success.
Expect	I don’t expect you to understand.
Tend	They tend to have an absent mind.
Would prefer	They’d prefer to come tonight.
Refuse	You guys can refuse to bail.
Pretend	Don’t pretend to be someone you’re not.

We use ‘to + infinitive’ after most adjectives to give a reason (happy, difficult etc).

Happy	My wife and I are happy to give you this gift as a token of our appreciation.
Difficult	The way the world can be difficult to master.
Big	You’re too big to challenge him.
Nice	It’s very nice to see you today.
Kind	It’s very kind of you to do that.
Mean	I was being mean in order to hurt them.
Grateful	I was being grateful to encourage you.
Proud	They are proud to be my parents in law.
Surprised	The locals were surprised to see me.
Anxious	I’m feeling anxious to wash the dishes.
Pleased	They are so pleased to meet us.
Sad	I’m sad to see you leave.

We use ‘to + infinitive’ to show purpose

I interviewed her to know what had happened.

I bought the vase to give to my mom.

Mary opened the door to see who was there.

We’re going to find the suspect to put him in jail.

I rang my mum to see how she was going.

You need to study a lot to pass your exam.

He turned the light on to see better.

Utilising the ‘to + infinitive’ construction can be a little tricky and It’s highly recommended that you read this article To & for that fully explains and elaborates on the usage of ‘to’ and ‘for’.

See also