薄い vs 細い
JLPT N5 vocabulary · what is the difference?
薄い is thin in thickness — a sheet of paper, a slice of meat — and by extension weak in flavour or pale in colour. 細い is thin in width — a narrow road, a thin line, slender legs. 薄い本 is a slim book with few pages; 細い道 is a road you can barely drive down. For a slim person you must say 細い, never 薄い.
When to use each
薄い
うすい
Use 薄い when something is flat and not thick: paper, books, slices, cloth, walls. It also covers weak taste, pale colour and thin hair. Its opposites are 厚い for thickness and 濃い for strength.
これは薄い紙です。
これはうすいかみです。
This is thin paper.
このスープは味が薄いです。
このスープはあじがうすいです。
This soup tastes bland.
細い
ほそい
Use 細い for things that are narrow across: roads, lines, string, pens, fingers, legs, a slim body. Its opposite is 太い.
この道は細いです。
このみちはほそいです。
This road is narrow.
彼女は指が細いです。
かのじょはゆびがほそいです。
She has slender fingers.
Sentences where only one works
この本は薄いです。
このほんはうすいです。
This book is slim.
A book's thinness is measured through the stack of pages, so 薄い. 細い本 would describe an unusually narrow page shape.
細い道を歩きました。
ほそいみちをあるきました。
We walked along a narrow path.
Width of a path is 細い. 薄い道 makes no sense.
妹は足が細いです。
いもうとはあしがほそいです。
My sister has slim legs.
Bodies and limbs take 細い. 足が薄い is not Japanese.
薄いピンクのカーテンを選びました。
うすいピンクのカーテンをえらびました。
I chose pale pink curtains.
Pale colour is 薄い, matching 濃い for dark. 細い never describes colour.
Common mistakes
彼女は薄いです。
彼女は細いです。
For a slim person, use 細い or やせている. 薄い about a person sounds like they are flat or faint, not slender.
細いコーヒー
薄いコーヒー
Weak drinks and weak flavour are 薄い, the opposite of 濃い. 細い only measures width.
Frequently asked questions
For a narrow road, is it 細い or 狭い?
Both are used. 細い道 pictures the road as a thin line, often a lane or path; 狭い道 says there is not enough room to pass. For a street too tight for two cars, 狭い is the more common complaint.
What are the opposites?
薄い pairs with 厚い for thickness and with 濃い for strength of taste or colour. 細い pairs with 太い.
How do I say a thin slice of meat?
薄い肉 or 薄切りの肉. Slices are about thickness, so 薄い. 細切り with 細い means cut into thin strips, which is a different shape.