This is the 6447th most frequent Korean word.
얼굴은
"얼굴은" means "face is" or "as for the face" in English.
In this sentence, "얼굴은" is used as the subject of the sentence, describing the appearance of someone's face.
그의 얼굴은 항상 밝다.
His face is always bright.
Here, "얼굴은" is used metaphorically to convey a general observation about faces.
얼굴은 마음의 창문이다.
The face is the window to the soul.
In this context, "얼굴은" serves to specify the object within the sentence that is not remembered.