【Subsequent Action】まえに【Prior Action】

Both the subsequent and prior actions will be independent clauses and thus end, like all sentences, in a verb.

The verb must be the present tense dictionary form. The reason this is a little confusing is because in English we put each clause in the tense corresponding to the timing of the action relative to the present. In other words, we would say:

Before I went to work I bought some cigarettes.

In Japanese, however, the tense of the first clause is independent from the tense of the latter.

仕事しごとまえに、コーヒーをむ。
Before I go to work I will drink coffee.
仕事しごとまえに、コーヒーをんだ。
Before I went to work I drank coffee.

As a native English speaker there is an innate desire to say:

仕事しごとったまえに、コーヒーをんだ。()

Unfortunately, this is not correct. Further, note the use of the target particle に after 前—we are talking about a point in time for the action.

いえ出掛でかけるまえに、電気でんきします。
Turn off the lights before leaving the house.
道路どうろたるまえに、左右さゆう確認かくにんします。
Look left and right before crossing the street.
くらくなるまえに、かえってきてください。
Please come back home before it gets dark.

For nouns we need to use the possessive particle, の.

かなら午前ごぜんまえ電話でんわしてください。
Please make sure you call before 9am.
説明会せつめいかいまえに、受付うけつけ自分じぶん名前なまえ登録とうろくしてください。
Before the seminar please register your name at the reception.

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