たことがあるhave done; have never done
Something is part of your experience: you have done it at least once in your life. With ない on the end, you never have.
I have been to Hokkaido.
I have never been on a plane.
How to form it
Verb た-form + ことがある
Never: たことがない. Polite あります, ありません. In conversation the が often drops: 行ったことある?
Asking and answering
Have you ever eaten natto?
No, I have never eaten it.
A short answer is enough too: はい、あります or いいえ、ありません.
Have you ever been to Okinawa?
English says "have been to". Japanese says 行ったことがある, with "went".
Once, several times, never
何度かseveral times
I have been to this restaurant several times.
Said inside the restaurant, so it is 来た, "came".
何度もmany times
I have seen that film many times.
一度も〜ないnever, not once
I have never worked abroad.
Things people say with it
聞いたことがある is how you say you have heard of something, and 見たことがある that something looks familiar.
I've heard that name before.
I've seen this person somewhere before.
I've never had ramen this good.
A common way to praise something.
Not every "have done"
English "have done" also covers something just finished. たことがある doesn't. And yesterday is too close to count as experience. Both take the plain past.
Not said: 昼ご飯は
(I've already had lunch.)
昼ご飯はもう食べました.
Not said: 昨日、
(I saw that film yesterday.)
昨日、その映画を見ました.
A time long ago is fine.
I have ridden a horse before, when I was a child.
When I was a student, I climbed Mount Fuji several times.
English switches to the plain past once a time is named. Japanese can keep たことがある.
And it has to be over. Something still going on is ている.
I live in Osaka.
Now. "I have lived in Osaka for three years" is this one too.
行ったことがある or 行くことがある?
I have walked to the office before.
た-form: it has happened at least once.
I sometimes walk to the office.
Dictionary form: it happens now and then.
Close neighbours
まだ〜ていないN5
"Not yet": it is still to come. たことがない says only that it has never happened.
I haven't seen that film yet.
Check yourself
1"I've already done my homework."
Choose an answer to see why.
2What does this mean?
父は
Choose an answer to see why.
More sentences
I have taught Japanese to overseas clients for work.
I have traveled by overnight train.
I have stayed overnight at a temple in Kyoto.