A rich aspectual system: Mandarin
As an example of a fairly rich system of aspectual markers, let’s consider Mandarin Chinese (Smith 1997). Aspectual markers are optional in Mandarin, and they are frequently omitted. When this happens, the aspectual interpretation of the sentence is flexible. Thus, (44) can receive either perfective or imperfective interpretation:

Since Chinese has no grammatical marking of tense, (44) can reasonably prompt the questions ‘is he still repairing it?’ and ‘did he finish repairing it?’.
If a speaker chooses to introduce aspectual meaning, Mandarin offers two perfective and two imperfective markers, each with a differing meaning. The perfective markers are le and guo. As perfectives, they present the situation as simple and closed – lacking any of the internal complexity associated with imperfectives. The following sentences show some typical uses of -le:

We said a moment ago that perfectivity is not the same as completion, and Chinese illustrates this very nicely. Thus, the perfective form in (46a) does not entail that the action be completed, as we can see in (46b); (46c) gives another example of the perfective used without the implication of completion:

Completion is signalled by an entirely different morpheme, wan, in (46b) and (46c).
Like -le, the second perfective marker, -guo, also presents a closed, simple situation. Unlike -le, however, it indicates that the final state of the situation no longer holds. In contrast to (45a), compare (47):

(45a) gave no information about whether the people referred to are still in Hong Kong; (47), on the other hand, tells us through -guo that the final part of the situation referred to by the verb no longer holds. The final part of the situation denoted by qu ‘go’ is being in Hong Kong: they must, therefore, no longer be in Hong Kong.
Here is another example of -guo, to be contrasted with (45b) above:

The final part of the event of breaking one’s leg is having a broken leg. -guo tells us that this situation no longer obtains: the leg must have subsequently healed.
The two Mandarin imperfective markers present the situation from an internal point of view. One of them, -zhe, has a resultative stative meaning which we will not discuss (for details, see Smith 1997: 273ff). The other, zai, is a typical imperfective with a meaning similar to the English progressive:

There are some differences between the English progressive and Mandarin zai, however. In English, verbs which denote instantaneous events can be compatible with progressive markers. It is possible to say he is winning the race or he is dying, even though winning a race and dying are strictly events which occur instantaneously. With both these verbs, the progressive means that the subject is in the lead-up to the occurrence itself. Mandarin zai does not allow this interpretation: instantaneous events are incompatible with zai, as the following examples show:

The impossibility of these sentences in Mandarin raises another set of important considerations. As we have just seen, what rules these sentences out is the incompatibility of imperfectivity with the inherent nature of the events concerned – winning a race, or dying. These events are, as we’ve seen, instantaneous; they just can’t be ‘stretched out’ in order to accommodate a progressive meaning. We might say that ‘win’ and ‘die’ are inherently perfective events. But, in this case, what about the English translations of (50)? How can win and die receive imperfective treatment in English if the verbs refer to inherently perfective events? We will consider the answer below.
QUESTION In the meantime, can you account for the acceptability of the English translations of (50a) and (50b)?