Mistaking.
The past participle of "mistake" is "mistaken."
Being is the present participle. The past participle is been.
Getting is the present participle of get.
The present participle is doing.
Presenting is the present participle of present.
Presenting is the present participle of present.
present / past / past participle cut / cut / cut Run / ran / run eat / ate / eaten have / had / had mistake / mistook / mistaken
The present participle is choosing.
The present participle is walking.
The present participle is cleaning.
The present participle is leading.
The present participle of "understand" is "understanding."