How to find common patterns in thousands of strings?

I don't want to find "abc" in strings ["kkkabczzz", "shdirabckai"]

Not like that.

But bigger patterns like this:

If I have to __, then I will ___.

["If I have to do it, then I will do it right.", "Even if I have to make it, I will not make it without Jack.", "....If I have to do, I will not...."]

I want to discover patterns in a large array or database of strings. Say going over the contents of an entire book.

Is there a way to find patterns like this?

I can work with JavaScript, Python, PHP.