~たことがある (past experience)

You've probably seen someone chanting "kuwabara kuwabara" after a flash of lightning — or done it yourself.

I want to hear about black magic. I've only heard a little at the academy, but I'm interested.

Come to think of it, I once had a tipsy old man sitting next to me on the train ask me to look at his haiku.

When evening came, he probably looked up at the starry sky with curiosity — or so I imagine.

One evening, I once stood atop this hill.

This is sudden, but have any of you ever felt looked down on by a younger person?

That's called a preconception! It's not okay to just decide things about stuff you've never even experienced!

N-no, that's not it — it's just that I never imagined there'd be someone who'd need me for who I really am.

Speaking of Nagoya, have you ever been to Seto?

I've been there, but it's not as great as its reputation suggests.

I've seen two of director Kurosawa's films.

Mother once won a swimming championship.

I've never seen such a beautiful night since I became old enough to remember.

She had never been heard speaking ill of others.

She's the most beautiful model I've ever seen.

She has the most stunning figure I've ever seen.

She has never been in love until now.

She talks about Paris as if she's been there many times.

She has been to Hawaii many times.

She talked about Paris as if she'd been there many times.

She had never been to see New York before, so I offered to show her around.

"Haven't I met you somewhere before?" the student asked.

I once spent a bit over a month in Nagoya.

I myself, at my company before this one, had the experience of speaking directly to the top twice or so.

There were also times when I took off work to watch the Super Bowl.

Have you also been a wizard at some point, Edgar?

Have you ever seen hail falling?

Speaking of travel, have you ever been to Australia?

Have you ever played baseball?

Have you ever written a book?