Grammar Point
adjective (keiyoushi)
adj-i 
多いおおい

many, numerous, a lot

large amount of, large quantity of, a lot, much

Noun + が + 多い

The word 多い is an い-adjective used to describe a large quantity or number of things. Unlike most adjectives, it is primarily used as a predicate at the end of a sentence or clause, rather than directly before a noun.

Predicate position

When describing a large quantity, the subject is marked with the particle が followed by the adjective 多い.

There are many books.

There were many students.

Note

In standard Japanese, it is considered ungrammatical to use 多い directly before a noun (e.g., 多い人 is usually avoided). Instead, use たくさんの before the noun or use 多い as a predicate at the end of the sentence. However, 多い can precede a noun if it is part of a longer adjective phrase, such as '人が多い町' (a town where there are many people).

Words: 
多いおおい
Radicals of radicals