How to say pretend to do something in English

1. Pretend (to) do something

If you pretend to know what you don't know, you'll only make a fool of yourself.

If you don’t understand, you will make a joke if you pretend to understand.

2. Pretend to be doing something.

Yet it needs, as a political matter, to pretend to be doing something.

However, from a political perspective, it still requires pretense and posturing.

3. Pretend to have done something

He pretended to have forgotten the conversation after that night.

He pretended to have forgotten what he said on New Year’s Eve.