What is the difference between ere and erre in spanish?

You're very close! There is no word "erre" in Spanish. You're likely thinking of "ere" and "err".

* "Ere" is a word that means "before" or "formerly". It is often used in phrases like "antes de", "antes que", "aquellos tiempos", etc.

* "Err" is not a word in Spanish. You are likely thinking of "error", which means "mistake".

Let me know if you have any more questions!