年間(ねんかん)

年間(ねんかん) emphasizes the span or duration of time in years, and can also function as a prefix meaning "annual" or "yearly."

Functions

1. Duration counter: 三(さん)年間(ねんかん)住(す)んだ (lived for three years) — emphasizes the full span
2. Prefix meaning "annual": 年間(ねんかん)売(う)り上(あ)げ (annual sales), 年間(ねんかん)計画(けいかく) (annual plan)

Common counting

• 一(いち)年間(ねんかん): one year (duration)
• 数(すう)年間(ねんかん): several years
• 十(じゅう)年間(ねんかん): ten years

CONTRAST WITH 年(ねん):
年(ねん) is the general counter for years (三(さん)年(ねん) = three years) and is also used for naming years (2024年(ねん)). 年間(ねんかん) specifically stresses the continuous period or span.