English compounded words!!?

I've checked four dictionaries -- not one of them lists "goodnight" as a legitimate word. Good night is correct. The fact that people combine the two doesn't make it right, it just makes it common.

One of the things that makes English so difficult is our multiple pronunciations for the same string of letters. For example: "ough." It is pronounced differently in each of these words: trough, though, tough, bough, through. How is anyone who is learning the language supposed to know how to say it?

because that's not how it worked out. :P