忘记已做了某事 forget doing sth

忘记做过某事了 forget doing sth

记得/忘了做过某事 remember/forget doing

忘记做过了某事 forget doing sth

忘记了去做某事 forget to do sth

忘记了要做某事 Forgetting to do sth

忘记了曾做过某事 forget doing sth

忘记已经做了某事 Forgot has already made something