1.
three years; period of three years
A duration of three years. The suffix 間 emphasizes a continuous span of time, distinguishing this from 三年 which can also mean 'third year.'
中学は三年間です。
Middle school lasts three years.
三年間留学していました。
I was studying abroad for three years.
この研究には三年間の時間と多くの努力がかかった。
This research took three years and a great deal of effort.
Adds the duration suffix 間 to 三年, making it unambiguously mean 'three years long' rather than 'third year.'
COMMON PATTERNS:
- 三年間続く: to continue for three years
- 三年間の経験: three years of experience
- 三年間勤める: to work for three years
SIMILAR WORDS:
- 三年: three years; third year — shorter form, can be ambiguous between duration and ordinal
- 三年生: third-year student — ordinal, not duration