1.
last year
The year before this one; the previous year. Used to refer to events or states in the year that just passed.
去年 means "last year" and is commonly used in everyday speech.
YEAR REFERENCE SERIES:
- 一昨年: year before last
- 去年: last year
- 今年: this year
- 来年: next year
- 再来年: year after next
COMMON PATTERNS:
- 去年の夏: last summer
- 去年から: since last year
- 去年の今頃: around this time last year
FORMALITY:
- 去年: casual/neutral
- 昨年: formal, used in writing and formal speech
Both 去年 and 昨年 can function as adverbs without particles.