I understand that ことはない is used to state that something does not have to be done, such as:
時間は十分あるから急ぐことはない。
However, I am currently translating a survey from Japanese to English for a friend and this phrasr is popping up often and I am not sure if I am translating it correctly. (He is a pyscology student if that matters).
Here are a couple examples that I am struggling with:
私は道にポイ捨てしたことはない。
or
自分の失敗をもみ消したことはない。
The second seems more straight forward, 'I don't need to hide my mistakes', but if that is the case, what is happening with the past tense of する? Why is it もみ消した and not もみ消す? my understanding is that when using this ことはない grammar point, the verb remains in dictionary form. The same applies for the second, example, is this saying I don't need to litter? Or rather that I don't litter? Or...I'm a bit lost?
Can anyone help me?
P.S. I apologize for any formatting errors, I am doing this on my iPad and it does not love this website.
Thanks!