have done before; have experience of
Form: verb in plain past + ことがある. Negative: 〜たことがない. Question: 〜たことがありますか — the classic have you ever…?.
Meaning: life experience — you did this at some undefined point in the past and it counts as a thing you've done. Not I did it yesterday; that's just plain past 食べた. This is I have (at some point) eaten it.
Crucial distinction — た vs plain form:
- 食べたことがある = have eaten (at least once in life).
- 食べることがある = there are times when I eat (it) — occasional habit, present tense. Completely different meaning; the tense of the verb before こと flips it.
Nuance: works for genuine experiences worth mentioning. Native speakers avoid it for everyday things — ご飯を食べたことがある I've eaten rice before sounds odd because of course you have. Use for travel, unusual foods, meeting people, rare events.
Politeness: the あります form is polite; ある is casual — the て-form and ことが chunk don't change.
Furigana is above every kanji; the pattern is already filled in.
日本に行ったことがありますか。
Have you ever been to Japan?
寿司を食べたことがある。
I've eaten sushi before.
その映画は見ことがない。
I've never seen that movie.