CONSISTENT VERB TENSE

动词 表达 a particular action (扔) or state of be荷兰国际集团(ing) (是). In addition, verbs help 表达 who or what performs the action (person), how many people or th荷兰国际集团(ing)s perform the action (number), the speaker's attitude toward or relation to the action (mood), whether the subject is the giver or receiver of the action (voice). Perhaps the most obvious characteristic of verbs, 然而, is how the verb 时态 表达 time.

Different verb forms are used in combination to 表达 when actions occur. The simple present, 过去的, 未来 时态 simply place events in time. The perfect 时态 (they occur with 有, 有, 有) 表达 events or actions completed; the progressive 时态 (-荷兰国际集团(ing) verbs used together with helpers such as is, 是, 是) show actions or events that are continu荷兰国际集团(ing).

Intentional shift荷兰国际集团(ing) of verb tense
A statement such as the follow荷兰国际集团(ing) intentionally mixes verb 时态:

I 有 decided to add Anthropology 11 when I discovered it already 有 filled up and the instructor 将 不 be accept荷兰国际集团(ing) any more students.

The mixed verb 时态 here are intended to convey in what order th荷兰国际集团(ing)s happened, what actions are completed, what actions are continu荷兰国际集团(ing). The class 有 filled and the speaker 有 decided (both actions completed in the 过去的) 之前 he or she discovered the class 是 full. And the instructor is at present turn荷兰国际集团(ing) away students and will continue to turn them away for the fore看到able 未来.

In the follow荷兰国际集团(ing) example, a statement about 过去的 actions is followed by a statement of a general truth:

I 有 decided to add Anthropology 11 when I discovered it already 有 filled up; it is unwise to wait until the last minute to add a required class.

Generalities and truisms 就像 this (it is unwise to wait) are 表达ed in the simple present tense, even if they are imbedded in a statement written in a 过去的 tense.

Unintentional shift荷兰国际集团(ing) of verb tense
Clearly, intentionally shift荷兰国际集团(ing) verb 时态 can convey a great deal of information. However, when verb 时态 shift for no good reason, mean荷兰国际集团(ing) becomes garbled. In general, avoid unnecessary changes in verb tense. This is a particular problem in personal narratives, where it is common to 看到 someth荷兰国际集团(ing) 就像 this:

I 是 undecided about my major when I 是 a freshman. I 想要 to study journalism but I 就像 艺术,也. I 找到 that sketch荷兰国际集团(ing) is relax荷兰国际集团(ing) and 帮助 reduce stress, while journalism 是 a high-energy, often stressful class.

The verb shifts are unnecessary and make it more difficult for the reader to follow. Here is the statement revised to a consistent 过去的 tense:

我是 undecided about my major when I 是 a freshman. I 想要 to study journalism but I 喜欢 艺术,也. I 发现 that sketch荷兰国际集团(ing) 是 relax荷兰国际集团(ing) and 帮助 reduce stress, while journalism 是 a high-energy, often stressful class.

In personal narratives, you may choose to use either 过去的 or present tense verbs. Just do 不 mix them as this writer did:

He 转 the key in the ignition, but only 听到 the relentless, useless chugg荷兰国际集团(ing) of an engine unwill荷兰国际集团(ing) to turn over. He 瞥了一眼 left, then right. He 不能 看到 the approach荷兰国际集团(ing) train through the driv荷兰国际集团(ing) rain, but he 可以 听到 it, a low moan荷兰国际集团(ing) wail still distant enough that he 认为 he still might be able to save the car.

Revised to a consistent 过去的 tense, this story is more coherent:

He 转 the key in the ignition, but only 听到 the relentless, useless chugg荷兰国际集团(ing) of an engine unwill荷兰国际集团(ing) to turn over. He 瞥了一眼 left, then right. He 不能 看到 the approach荷兰国际集团(ing) train through the driv荷兰国际集团(ing) rain, but he 可以 听到 it, a low moan荷兰国际集团(ing) wail still distant enough that he 认为 he still might be able to save the car.

In this case, 然而, you might be more successful in recreat荷兰国际集团(ing) the suspense of the moment by keep荷兰国际集团(ing) to a consistent present tense:

He 转 the key in the ignition, only 听到 the relentless, useless chugg荷兰国际集团(ing) of an engine unwill荷兰国际集团(ing) to turn over. He 目光 left, then right. He 不能 看到 the approach荷兰国际集团(ing) train through the driv荷兰国际集团(ing) rain, but he 可以听到 it, a low moan荷兰国际集团(ing) wail still distant enough that he 认为 he still might be able to save the car.

The literary present tense
For discuss荷兰国际集团(ing) literary works, the preferred tense is the present:

Author Michael Crichton frequently addresses bioethical questions of this sort. 他的 Jurassic Park character Ian Malcolm is a kind of devil's advocate, a doomed protagonist who 问 the unasked question: "We can--but should we?"

This statement includes one about the author and his intentions or techniques, a不her about a character in one of his books; both are constructed in the literary present tense. Use literary present tense for book and article reviews, summaries, critiques.

Critiques of musical performances, art shows or other artistic works also may use the literary present tense.

For more information on verbs, 看到 the TIP Sheet 动词.