N4
さ
Converting adjectives to nouns
私が道の長さを測ります。
I'll measure the length of the road.
Explanation
「さ」 added to an adjective stem makes a noun for the degree of that quality.
「高い→高さ」 (height), 「重い→重さ」 (weight), 「長い→長さ」 (length), 「深い→深さ」 (depth), 「大切な→大切さ」 (importance).
「荷物の重さを測る」 (weigh the luggage).
Mixed up with
「さ」 gives a measurable degree and works with almost any adjective.
「み」 gives a felt quality or a part that has the quality: 「悲しみ」 (sorrow), 「深み」 (depth, deep part), 「甘み」 (sweetness). Only a few adjectives take 「み」.
Easily confused withさ・み: the difference ›