を見たことがない

have never seen

→ を
phrase Uncommon #9,635
have never seen Expresses that someone has never seen something or has no experience of seeing it. The pattern is noun or phrase + を見たことがない.
JA: 青い犬を見たことがない。
EN: I have never seen a blue dog.

を見たことがないのだろうか

Have you never looked in a mirror?

私はいままでそんな頭の良いを見たことがない

I've never seen such a smart child before.

こんなに美しいを見たことがない

I've never seen such a beautiful painting.

赤い冷蔵庫を見たことがない

I've never seen a red refrigerator.

俺は俺はまだあの時ほど美しいを見たことがない

I... I've never seen a wife as beautiful as she was that day.

— 羅生門 (1950)

これまで訪れた中でエベレストほど美しいを見たことがない

Of all the mountains I’ve visited, I’ve never seen one as beautiful as Everest.

トムメアリーすごく怒っているとこを見たことがない

Tom has never seen Mary really angry.

だれもその鳥が飛ぶを見たことがない

No one has ever seen that bird fly.

私は生きているを見たことがない

I've never seen a live whale.

そんなひどい事故を見たことがない

I've never seen such a terrible accident.

それをしてみたを見たことがない

I've never seen anyone try that.

今までに本物のを見たことがない

I've never seen a real cow before.

トムが泣いてるのを見たことがない

I've never seen Tom cry.

私は今までにこんなに不思議なを見たことがない

I've never had such a strange dream before.