Chinese, a tenseless language, has no formal change corresponding to tense distinctions, and tense does not mark the verb. Besides, there is no formal marker for the tense distinctions and no grammatical tense. But Chinese uses different ways to indicate the time reference.
In Chinese, temporal adverbials are usually added to indicate the time reference. (Tsai, 2008) For example 我做完功課就去玩, the time reference is unclear. Adding time adverbials can make the sentence self-sufficient. For example, 我昨天做完功課就去玩 and 我等下做完功課就去玩, 昨天 and 等下 work as a time adverbials to show the time. Hence, the reference times of the sentences become identifiable.
Moreover, the temporal meanings and functions of aspectual markers in Chinese are references to the time. For example, although 過 and 了 are both involving the result event, they do not have the same function. 過 is used in repeatable conditions, working as an experiential marker, while 了 works as a perfective or imperfective marker to report an actual event. Taking 我看過電影 and 我看了電影 as examples. In the condition of using 過, the movie has to be once seen first, a completed event before the speech time. It describes an experience that I have watched movies before for once or more. In the condition of using 了, even though it is also a finished event, it only marks the actualization that I have watched movies without mentioning my experience.
Apart from 過 and 了, 在(progressive marker) and 著(duration marker) can indicate the continuation of an event, which provide hints for the learners to find out the time. (Lin, 2005)
Tsai, W. T. D. (2008). Tense anchoring in Chinese. Lingua, 118(5), 675-686.
Lin, J.-W. (2005). Time in a language without tense: The case of Chinese. Journal of Semantics,
23(1), 1–53. https://doi.org/10.1093/jos/ffh033