If you are talking about something that is completely in the past, you use the Past Tense (sometimes called the Imperfect), e.g.

如果所谈论的事情完全发生在过去，则用过去时态(有时也叫做未完成时态)，例如：I used to live in Seattle /我过去住在西雅图。

youdao

A Spanish verb has six present-tense forms, and six each in the preterite, imperfect, future, conditional, subjunctive and two different past subjunctives, for a total of 48 forms.

西班牙语的动词现在时有六种形态，过去时、未完成时、将来时、条件句、虚拟句以及另外两种过去时虚拟式也各自有六种形态，加起来一共是48种。

youdao

Learning all forms for every verb can be exhausting, especially for the dreaded imperfect or simple past.

学习每个动词的所有形式可谓是非常累的，特别是那些恐怖的不规则过去分词和过去式。

youdao

But no such adaptive change is seen in collections of hoverflies made over the course of the past two centuries, suggesting that the imperfect mimics are stable in evolutionary terms.

ECONOMIST: Insects and mimicry

And yet the relation between economic data - which are often imperfect, and can only represent the state of an economy as it was some time in the past - and the future is tenuous at best.

BBC: A Point of View: And all shall worship money

"A few misguided appellate court decisions are threatening the imperfect but delicate balance of Hatch-Waxman, one that has yielded enormous benefits for consumers over the past 20-plus years, " Leibowitz said in prepared remarks.

FORBES: Patent Wars