There are many verbs that take either an infinitive or gerund. Some take only one. This verb does not take an infinitive.
Student or Learner
"She avoids talking to him."
"She avoids to talk to him."
I find the second one rather unnatural, but can someone please explain the rules behind this?
NOT A TEACHER.
Please correct all my mistakes.
(copied from Boris Tatarenko)
It's not really a question of rules. Some verbs take gerund and others infinitives, some with others without to - but this is mostly arbitrary. There is no answer to why- we do it because everyone else does.