到 can be used after a verb to express the state of an action. Its best not to think of it in terms of tense. I'd say it best translates as arrive, as in to reach a point (similar but not quite the same as completion). So, you could say ”票买到了吗？“ have you bought the tickets, and (if its chinese new year) the other person might respond: ”买不到“ the tickets can't be bought, too much demand and not enough supply. Similarly, your boss might tell you "把这个项目做到“ Get this project done! To make sense of the grammar I think in my head: 做 this project, and do it until 到, something like do this project until it arrives at the end. So, while the first one is kinda past tense, the second one strictly isnt. This is just one case (of many) where you need to remember Chinese grammar is heavier on aspect and lighter on tense.

到 can be used after a verb to express the state of an action. Its best not to think of it in terms of tense. I'd say it best translates as arrive, as in to reach a point (similar but not quite the same as completion). So, you could say ”票买到了吗？“ have you bought the tickets, and (if its chinese new year) the other person might respond: ”买不到“ the tickets can't be bought, too much demand and not enough supply. Similarly, your boss might tell you "把这个项目做到“ Get this project done! To make sense of the grammar I think in my head: 做 this project, and do it until 到, something like do this project until it arrives at the end. So, while the first one is kinda past tense, the second one strictly isnt. This is just one case (of many) where you need to remember Chinese grammar is heavier on aspect and lighter on tense.

both mark that the action is done。 到 emphasis the purpose of the action is achieved。 过 emphasis the procession of the action is finished。

‘到+certain time’means the period including that point in time and the period just before that,while ‘过+certain time’means the period which consists of that point in time and the period before that and a long or short period right after that point in time as well.

刀？ knife？ 是到吧