Here are a few examples:
* Bet - "I bet on the horse." (present) "I bet on the horse yesterday." (past)
* Cut - "I cut the bread." (present) "I cut the bread earlier." (past)
* Hit - "I hit the ball." (present) "I hit the ball last night." (past)
* Hurt - "This hurts!" (present) "I hurt my knee." (past)
* Let - "I let the dog out." (present) "I let the dog out earlier." (past)
* Put - "I put the book on the shelf." (present) "I put the book on the shelf yesterday." (past)
* Quit - "I quit smoking." (present) "I quit smoking last year." (past)
* Read - "I read a book." (present) "I read a book yesterday." (past)
* Set - "I set the table." (present) "I set the table before dinner." (past)
* Shut - "I shut the door." (present) "I shut the door before I left." (past)
There are many more irregular verbs in the English language.