Tenses is a form of the verb in the English language to indicate the time (present, future, or past) the occurrence of an act or event. See also: Sequence of tenses (Some Verb Tense in a circuit) Passive Form on tenses.
simple present tense
(S + V-1)

positif (+)	S + Verb-2 (past tense) S + be(was/were)	The teacher came
		I was a stamp collector
negatif (-)	S + did + not + bare infinitive S + be(was/were) + not	The teacher didn’t come
		I wasn’t a stamp collector
interogatif (?)	Did + S + bare infinitive be(was/were) + S	Did the teacher come
		Was I a stamp collector

simple past tense
past tense to talk about the action that occurs at a specific time duration in the past. Preposition "for" can be used to declare a period of time of incident.

Vina and I went to the Ragunan zoo three months ago. (Saya dan Vina pergi Ragunan tiga bulan lalu.)

Did he come on time yesterday? (Apakah dia datang tepat waktu kemarin?)

The party started at 10.00 a.m. (Pesta mulai jam sepuluh pagi.)

Did you sleep enough last night? (Apa kamu cukup tidur semalam?)

I studied civil engineering for almost 4 years. (Saya belajar teknik sipil selama hampir 4 tahun.)