He looks sad / he doesn't look happy.

He's frowning. 他在皺眉頭。
He's chuckling. 他在抿嘴笑。
He's squinting. Probably because of the sunlight.
他瞇著眼睛，大概是因為陽光刺眼。

He's old. / He's foreigner.

I think he's European. He could be Italian or Portuguese.
我想他是歐洲人，可能是義大利人或葡萄牙人。

It looks like he's in his fifties or sixties.
他看起來大概五、六十歲。

He has prominent / deep wrinkles on the forehead and near his eyes.
他額頭和眼周的皺紋很深。

He has thin and dark hair. Some of his hair turned white, though.
他有稀疏、深色的頭髮。有些頭髮已經變白了。