The grammatical form that denotes a single item (singular form), used for nouns/pronouns in languages that distinguish number.
英語では『book』が単数形で、『books』が複数形だ。
In English, 'book' is the singular form and 'books' is the plural form.
日本語は語形変化で単数形と複数形を明確に区別しないことが多い。
Japanese often doesn't clearly distinguish singular and plural by form changes.
文法問題で主語が単数形のときは動詞も単数形に合わせる。
In grammar exercises, when the subject is singular, the verb should be matched to the singular form.