is a set expression in Japanese that is used for saying that ‘there has been a time that I have done (A)’.
The auxiliary verb た
will be added to the verb indicating what you have done, followed by こと
. Like の
is regularly used for nominalization (creating a noun-like phrase). However, の
cannot replace こと
in this particular grammar pattern.
Have you ever been to Mt. Fuji before?
I have never bought snacks.
From these examples, we can see that ない
(the negative equivalent of ある
) may also be used, when you want to express that you have ‘never’ done something.
Caution - Just like English, many set phrases cannot be adjusted in Japanese (in the same way that こと cannot be swapped with の in this expression).
Fun-fact - In expressions where こと
is followed by a verb phrase, の
may not be used. When used for nominalization, の
is almost always followed by a noun or adjective phrase. Here are some examples.
He can do things like dance.
Because I have no work next week, I have decided to go traveling.
Today, I will end up coming home late.