Kare no yasashisa wa honmono desu
n this section, you will learn how to transform adjectives into nouns, often called nominalization. In English, the suffix ‘…ness’ is frequently used to achieve this, as in the words ‘happiness’ or ‘sadness.’
…sa
An i-adjective is a type of adjective in Japanese, while a noun-adjective functions both as an adjective and a noun. To turn an i-adjective into a noun, you simply change the final i-sound to ‘…sa,’ which expresses the degree or extent of the adjective’s quality. Although this transformation primarily applies to i-adjectives, the suffix ‘…sa’ can also be added to noun-adjectives to create nouns.
ookii (big) >>> ookisa (bigness)
yasashii (kind) >>> yasashisa (kindness)
amai (sweet) >>> amasa (sweetness)
ii (good) >>> yosa (goodness)
seiketsu (noun-adjective: clean) >>> seiketsusa (cleanliness)
juuyou (noun-adjective: important) >>> juuyousa (importance)
Expression
Kono hako no ookisa wa donokurai desuka? Omosa wa doudesuka? (How is the bigness of this box? how is the heaviness?)
Tuskarete imasuka? Isogashisa ga kao ni deteimasu. (Are you tired? I can see your busyness from your face.)