You often hear people saying that Chinese has simple grammar, and the most often cited reason is that “Chinese has no tenses.” It’s true that Chinese verbs do not have tenses, but Chinese grammar does have a formal system for marking aspect. What is aspect? Most English speakers don’t even know.
I’ll quote from the Wikipedia entry on aspect:
In linguistics, the grammatical aspect (sometimes called viewpoint aspect) of a verb defines the temporal flow (or lack thereof) in the described event or state. In English, for example, the present tense sentences “I swim” and “I am swimming” differ in aspect (the first sentence is in what is called the habitual aspect, and the second is in what is called the progressive, or continuous, aspect). The related concept of tense or the temporal situation indicated by an utterance, is typically distinguished from aspect.
So if the temporal situation (tense) of a verb is typically distinguished from aspect, shouldn’t we English-speakers be more familiar with it?
It turns out the situation is a bit muddled in English. From the same article:
Aspect is a somewhat difficult concept to grasp for the speakers of most modern Germanic languages, because they tend to conflate the concept of aspect with the concept of tense. Although English largely separates tense and aspect formally, its aspects (neutral, progressive, perfect and progressive perfect) do not correspond very closely to the distinction of perfective vs. imperfective that is common in most other languages. Furthermore, the separation of tense and aspect in English is not maintained rigidly. One instance of this is the alternation, in some forms of English, between sentences such as “Have you eaten yet?” and “Did you eat yet?”. Another is in the past perfect (“I had eaten”), which sometimes represents the combination of past tense and perfect aspect (“I was full because I had already eaten”), but sometimes simply represents a past action which is anterior to another past action (“A little while after I had eaten, my friend arrived”). (The latter situation is often represented in other languages by a simple perfective tense. Formal Spanish and French use a past anterior tense in cases such as this.)
OK, it’s starting to become clearer why English-speakers aren’t familiar with aspect. But what’s this business about “English largely separates tense and aspect formally”?
According to one prevalent account, the English tense system has only two basic tenses, present and past. No primitive future tense exists in English; the futurity of an event is expressed through the use of the auxiliary verbs “will” and “shall”, by use of a present form, as in “tomorrow we go to Newark”, or by some other means. Present and past, in contrast, can be expressed using direct modifications of the verb, which may be modified further by the progressive aspect (also called the continuous aspect), the perfect aspect, or both. These two aspects are also referred to as BE + ING and HAVE +EN, respectively.
Wikipedia also brings up how Mandarin Chinese fits in with regard to aspect:
Aspect, as discussed here, is a formal property of a language. Some languages distinguish different aspects through overt inflections or words that serve as aspect markers, while others have no overt marking of aspect. […] Mandarin Chinese has the aspect markers -le, -zhe, and -guo to mark the perfective, durative, and experiential aspects, and also marks aspect with adverbs….
If you study modern Chinese grammar, you’ll learn that Mandarin has three aspectual particles (时态助词): 了, 着, and 过. It would be nice if that were all there was to it, but the Chinese situation, similar to the English one, is a bit muddled. That’s about as clear as it gets.
In the case of 了, the word has a split personality and sometimes acts as an aspectual particle, sometimes as a modal particle (语气词), and sometimes both. There is endless fun to be had studying 了 (I know; I took several syntax classes in grad school).
着, on the other hand, is sometimes relieved of its aspectual duties by the adverbs 正 or 在 (or 正在). But then there are some that say that would prefer to draw fine distinctions between these usages as well.
It’s funny to think that Chinese grammar is still in its “Wild West” stage. Linguists are still debating all kinds of fundamental issues of grammar, both within China and without. While you can say with conviction that “Chinese has aspect, not tense,” you can’t say a whole lot more than that. For learners who want to “know the rules,” this can be more than a little frustrating. The good news is that, like all languages, it rewards the persistent. The Kool-aid tastes downright weird at first, but if you just keep drinking it, it starts to taste right.
(If, however, you’re really interested in this whole aspect thing, I recommend you check out Mandarin Chinese: A Functional Reference Grammar, which is about as close as you can get to “classic” in this turbulent field. It has over 50 pages devoted to aspect, with plenty of examples, but be warned: no Chinese characters!)