Q: We see many times throughout the plagues that Hashem ‘hardened Pharo’s heart’, seemingly denying Pharoh the ability to repent and to let the people go! Did Pharoh not have freewill! A: The Chafetz Chayim explains that there are 2 types of repentance:
a) Repentance that Hashem does for us. Siyata Dishmaya. Hashem brings us up without us doing much of the work
b) Repentance that we do ourselves. When Hashem hardened Pharoh’s heart, Hashem removed option ‘a’ from Pharoh, but he still had the freechoice nonetheless to repent if he sincerely desired to do so.