Let's look here at examples of verbs taking the infinitive without 'to':
They let us use their apartment for the summer.
The driving examiner made me repeat the test.
The parents made the children tidy the room before the visit
Note that the second verb here is the infinitive but 'to' is not needed. This is usually the case when the first verbs are 'let' or 'make'.
We also had some verbs which can be followed by either a bare infinitive or the -ing form:
see, observe, hear, overhear, watch, notice
although sometimes with a change of meaning:
Did you hear those dogs barking the whole night? (=repeated action)
Did you hear that dog bark at 3 am? (=single action)
I watched them building that house. (=over a period of time, continuous repeated action)
I watched them build that house (=single completed action)
I noticed him putting the key in his pocket. (=I did not see the complete action)
I noticed him put the key in his pocket. (=I saw the complete action)
Remember also that some verbs can take a gerund, but usually after an object:
We found him drinking again.
We discovered the whole class sitting out in the sun.
She overheard them talking about the wedding plans.
(Note: Passive forms of the above sentences would be:He was found drinking again.
The whole class were discovered sitting out in the sun.
They were overheard talking about the wedding plans.)
There are also verbs which take an infinitive, but usually after an object:
She asked them to turn down the music.
We urge everybody to calm down and start negotiating.
I told her to be here at midday.
Are you confused? Don't worry. It takes time and a lot of practice to learn when to use a gerund and when to use an infinitive. But it is worth doing exercises in this area and making your own personal list of verbs to remember. A lot of the gerund-only verbs (look forward to, propose, consider) are used in memos.
