How do you use pseudo in a sentence without using as prefix to another word?

You can't use "pseudo" as a word on its own in English. It always functions as a prefix, meaning "false" or "imitation."

For example, you could use "pseudo" in a sentence like this:

"The pseudo-scientific claims made by the conspiracy theorists were easily debunked."

In this example, "pseudo" modifies the word "scientific" to create a new word meaning "fake scientific."