～前に
before / ago (temporal)
～前に（まえに）marks the time before an action or event. It follows a verb in the dictionary form (寝る前に, “before sleeping”) or a noun + の (食事の前に, “before the meal”).
After a length of time, the same 前に means “ago” (三年前に, “three years ago”).
1. Before an action
The verb before 前に is always in the dictionary form, even when the whole sentence is about the past.
寝る前に歯を磨いた。
“I brushed my teeth before going to bed.”
- 寝る（ねる）= to sleep, go to bed
- 前に（まえに）= before
- 歯（は）= teeth
- を = object marker
- 磨いた（みがいた）= brushed (past of 磨く, to brush)
2. Before a noun event
With a noun, insert の before 前に.
食事の前に手を洗う。
“I wash my hands before meals.”
- 食事（しょくじ）= meal
- の = links the noun to 前に
- 前に（まえに）= before
- 手（て）= hands
- を = object marker
- 洗う（あらう）= to wash
3. “Ago” with a length of time
三年前に日本に来た。
“I came to Japan three years ago.”
- 三年（さんねん）= three years
- 前に（まえに）= ago
- 日本（にほん）= Japan
- に = destination marker
- 来た（きた）= came (past of 来る, to come)
～前に is the mirror image of ～後で (“after”). Watch the verb forms: the dictionary form goes before 前に, but the た-form goes before 後で.
How to form it
Verb dictionary form + 前に / Noun + の前に / length of time + 前に
- 寝る（ねる）= to sleep → 寝る前に（ねるまえに）= before sleeping
- 食事（しょくじ）= meal → 食事の前に（しょくじのまえに）= before the meal
- 三年（さんねん）= three years → 三年前に（さんねんまえに）= three years ago
Key idea
Whatever stands before 前に is the later event; the main clause happens first. And no matter the tense of the sentence, the verb before 前に stays in the dictionary form.
Other N3 grammar
Updated .