I am not sure about the usage of infinitives in this sentence:
Finally, one of the accused confessed to have forged the director's signature on the report.
Could anyone explain correct usage?
English Language & Usage Stack Exchange is a question and answer site for linguists, etymologists, and serious English language enthusiasts. It only takes a minute to sign up.Sign up to join this community
You seem to have confused the to particle used in certain infinitive constructs with to used as a preposition.
In English, the phrasal verb confess to takes the -ing form of the verb as its complement, not a bare infinitive as you have used here.
This acts as the head of its own verb phrase (VP), and is effectively a noun. When you use an -ing form as a noun, it is sometimes called a gerund. Notice how you can swap in a real noun:
There is also a non-phrasal use of confess, as distinct from the phrasal verb confess to: