Learn Hardcore Japanese: kanozyo ha kanasii kao wo site ita.

It literally combines 顔 (face) + を (object) + する (to do), but idiomatically it means “to have/wear/make [a kind of] expression.” So 悲しい顔をしている = “to be wearing a sad expression.” The 〜ている marks a continuing state; in the past, 〜ていた is a continuing state in the past.

Why is を used with 顔 instead of が?

Because 顔をする is a set idiom where 顔 is treated as the direct object of する. You “do” a certain face/expression. Using が here would be ungrammatical in this pattern. Compare: においがする (a smell occurs/there is a smell) uses が, but expressions with 顔 use を.

What’s the role of は in 彼女は?

は marks the topic: “as for her.” It sets “her” as the frame, and then tells you about her expression. If you used が (彼女が悲しい顔をしていた), you’d be emphasizing that it was she (and not someone else) who had that expression.

Why is it していた and not した?

〜していた (the past of 〜している) describes an ongoing state in the past—she was in that state of having that face. 〜した would suggest a single, momentary act: “she made a sad face (for a moment).” So 〜していた matches “was wearing/was looking” better.

Is 〜ていた here a “past progressive”?

Functionally yes, but note that with stative/expressive patterns like 顔をしている, 〜ている often describes a state rather than an action in progress. So 〜ていた places that state in the past.

Could I just say 彼女は悲しかった?

You could, but it asserts her internal emotion (“she was sad”), which implies knowledge of her feelings. 悲しい顔をしていた only reports what you saw (her expression), without claiming you know how she felt.

What’s the difference between 悲しい顔をしていた and 悲しそうだった?

悲しい顔をしていた focuses on the visible expression (she was wearing a sad face).
悲しそうだった uses 〜そう (“seems/looks”) and highlights your impression or inference (“she looked sad”).
If she was faking it, 顔をしていた still works neutrally; 〜そう is about how she appeared to you.

How is it different from 悲しく見えた?

〜見える explicitly frames it as your perception: “(to me) she looked sad.” You’ll often see it with 私には: 私には悲しく見えた. 悲しい顔をしていた doesn’t foreground the observer; it states the observable expression.

What about 悲しげだった?

〜げ attaches to adjective stems and means “having an air of ~,” often a bit literary/formal. 悲しげだった ≈ “had an air of sadness.” It’s subtler and more stylistic than the everyday 悲しい顔をしていた.

Is 彼女は悲しい顔だった correct?

No. That says “She was a sad face,” which mismatches subject and complement. Say 彼女は悲しい顔をしていた (she had a sad face) or 彼女の顔は悲しかった (her face was sad).

Is 彼女の顔は悲しかった okay? What’s the nuance?

Yes, it’s fine. It makes “her face” the topic and describes its state. 悲しい顔をしていた is more idiomatic for “she wore a sad expression,” while 彼女の顔は悲しかった directly characterizes the face.

Why not say 彼女の顔をしていた?

Because the pattern needs a descriptor before 顔. You “do” a certain kind of face: 悲しい顔, 変な顔, 真剣な顔, etc. 彼女の顔をしていた would mean “was making her face,” which doesn’t make sense unless you say something like 誰々のような顔をしていた (“had a face like X’s”).

Can I drop 彼女は?

Yes. Subjects are often omitted when clear from context: 悲しい顔をしていた would be natural if “she” is already known in the conversation.

How would I say this politely?

Use です/ます style: 彼女は悲しい顔をしていました.

How does this look in casual speech?

You’ll hear contractions and particle drops:

彼女、悲しい顔してた。
悲しい顔してたよ。
Here していた → してた, and は/を can drop in casual talk.

What other words can I use with 顔をしている?

Common modifiers include:

嬉しそうな顔をしている (wears a delighted face)
変な顔をしていた (was making a weird face)
真剣な顔をしている (has a serious look)
怒った顔をしている (has an angry face)

Is there a more formal alternative to 顔?

Yes: 表情 (expression). 悲しい表情をしていた is a bit more formal/written. Same structure and meaning.

Is 顔をする only for faces?

The broader pattern N をしている can mean “to have N (as an attribute).” Examples:

いい声をしている (has a nice voice)
細い体をしている (has a slim body)
変な癖をしている (has a strange habit) With 顔, it specifically means wearing/making a certain expression.

How would I say “Don’t make that face”?

Use the negative imperative with する:

そんな顔をしないで。 / そんな顔しないで。

How do I pronounce the sentence?

かのじょはかなしいかおをしていた (kanojo wa kanashii kao o shite ita).