たくさん

たくさん expresses a large quantity, usable as both adverb and noun.

GRAMMAR:

• As adverb: たくさん食(た)べる (eat a lot)
• As noun: たくさんの人(ひと) (many people)
• With が: たくさんがある is less common; use たくさんある

USAGE:
Can modify both countable and uncountable nouns.

COMMON PATTERNS:

• たくさんある/いる: there are many
• たくさん〜する: do something a lot
• たくさんの〜: many/much (noun modifier)

SIMILAR WORDS:

• 多(おお)い: many (adjective, cannot directly modify nouns: ×多(おお)い人(ひと))
• いっぱい: full, lots (more casual)
• 大量(たいりょう)の: large quantity of (formal)

ANTONYMS:

• 少(すこ)し: a little
• ちょっと: a bit (casual)