nominalizer N4 common casualpolitewritten

さ — nominalizing suffix (degree: 高さ)

さ

Meaning

-ness / -ity / degree of ~ — turns an adjective into a noun naming its measurable degree

この山やまの高たかさはどのくらいですか。

How tall is this mountain (lit. what is its height)?

Attaches to	Form	Example
i-adjective (drop い) / na-adjective	Adj-stem + さ	高たかい → 高たかさ; 静しずか → 静しずかさ

荷物にもつの重おもさを量はかる。

I weigh the luggage (measure its weight).

彼かれの優やさしさに感動かんどうした。

I was moved by his kindness.

部屋へやの広ひろさに驚おどろいた。

I was surprised at how spacious the room was.

さ measures an objective, scalable degree (高たかさ, 長ながさ, 重おもさ). The rarer 〜み (深ふかみ, 重おもみ) names a subjective quality you sense rather than a number — 重おもさ is weight in kilos, 重おもみ is a felt gravity or significance.

Jengo shows さ the way you actually meet it: inside real Japanese sentences, so it sticks instead of staying an abstract rule.

Sources Compiled with reference to A Dictionary of Basic Japanese Grammar, A Dictionary of Intermediate Japanese Grammar.