what are the tenses possible after "to"

[Unregistered]

what are the tenses possiblities after "to"


example:

1, i am happy to have found this site.


and so on.

pls give me explanation and
possiblities.....etc

[rancher247]

Well an infinitive generally comes after "to".
If you look at the translations of romance languages' verbs into english, there's generally a to in front of the infinitive.
cantar/cantare=to sing

[Clare James]

With infinitive forms you can have these structures:-
the basic infinitive: 'to know'
the passive infinitive form: 'to be known'
the perfect infinitive form: 'to have known'
the passive perfect infinitive form: 'to have been known'

(But you can't change the infinitive in any other way to communicate a tense change: 'to will know', for example is incorrect.)