Most verbs have an active infinitive form (with or without to): (to) catch, (to) do, (to) help, (to) leave, (to) wash.
Most verbs also have a passive infinitive form, which consists of the infinitive of be (with or without to) + the -ed form of the main verb: (to) be caught, (to) be done, (to) be helped, (to) be left, (to) be washed.
The police are determined to catch the murderer.
The police are confident that the murderer will be caught soon.
Come on, there’s work to do!
There was no more work to be done, so we left.
Let me help you.
She doesn’t want to be helped.
I didn’t want to drive home, so I got a taxi.
I’d always prefer to be driven by a local person when I’m in a foreign country.
Focus on the agent
We use the active infinitive if we are focusing on the agent (the person who does the action):
The doctor gave me an eye-patch to wear.
Not: The doctor gave me an eye patch to be worn. (‘me’, the agent – I will wear the eye-patch)
She brought a portable chair to sit on – the rest of us had to sit on the grass.
Not: She brought a portable chair to be sat on … (‘she’, the agent – she will sit on the chair)
Focus on the receiver or the action
We use the passive infinitive when we want to focus on the receiver (the person who experiences the action), or when we do not want to mention the agent (the person who does the action):
I didn’t give out my email address because I didn’t want to be contacted by strangers. (I am the receiver, the person ‘to be contacted’)
Ben was hoping to be chosen for the rugby team, but he didn’t do very well in the trials. (It is not important to mention the agent; to say who would choose him.)
After there is, there are
The difference between the two infinitive forms is often very small when we use a there is or there are construction to talk about obligation:
Come on! There’s work to do. or Come on! There’s work to be done. (There is work that we must do.)