A verb is a word that expresses action, or indicates a state of being. Tense is a quality of a verb that indicates the time when an action (i.e., the action expressed by the verb) occurred. Verb tense, therefore, is the time when an action happens.
The most commonly-used tenses are past, present, and future. In the English language, verb tense must coincide with sentence tense (i.e., the tense of the sentence of which the verb is a part), unless the verb tense is being used to indicate a shift in time within the sentence. Verb tense should be consistent throughout a written work, unless there's a shift in time within the work.
EXAMPLEAs your coworker began telling you what she did yesterday, she stated that she "got up, made breakfast, and went to work." All of the verbs she used agree in terms of tense: they are all stated in past tense. However, if she continues her account by saying that she "ate lunch, returned to work, and get a promotion," do you notice any inconsistency in her use of tense?
Although native speakers of English may be amused by misuse of tense, most of them would understand your coworker's meaning. However, listeners or readers whose first language is not English may be confused, perhaps missing your coworkers meaning altogether. Even native users who use tense correctly when speaking, sometimes mix tenses when writing. This is sometimes the result of beginning a written sentence with one idea in mind, and ending it with another.
Verb tense inconsistencies, like those presented in the example above, often go unnoticed by speakers — and writers. They don't realize that they have shifted tense within sentences, between past, present, and future. Careful attention, proofreading, and writing practice help writers to avoid and correct this problem.
Verb tense consistency, like many aspects of the study of grammar, is easier to see than to explain. Following are several examples which demonstrate inconsistency in verb tense:
Tomorrow he turned 15 years old.
This sentence contains an error in verb tense. The verb used in the sentence (i.e., the past-tense form of "to turn") must agree with the future tense of the sentence, indicated by "tomorrow," as in the following revision:
Tomorrow he will turn 15 years old.
Is there a problem with the verb tense in the following sentence?
They left for Mexico next week.
This sentence should not only sound wrong, but it should also look illogical. It can be corrected by making the tense of the verb "to leave" agree with the tense of the sentence:
They will leave for Mexico next week.
The following example is a bit more complicated than the preceding two:
Even now, years after the breakup, she still loved him.
Have you spotted the problem? It's at the end of the sentence: "She still loved him" doesn't agree with the tense of the sentence. It can be corrected with a revision similar to the following:
Even now, years after the breakup, she still loves him.
Sometimes writers make a different kind of mistake when it seems to them that verbs should change tense, but they should not. Here's an example:
Even though I bought the boat last year, I still dreamt about it.
This sentence would probably sound wrong to you if you had heard it spoken, but you may not have noticed the problem when reading it. Both of the verbs used in the sentence are in past tense so, at first glance, it may seem to be correct. However, the second verb should be in present tense, because the speaker is indicating that he or she continues to dream about the boat now:
Even though I bought the boat last year, I still dream about it.
Here is another example:
Last night's fishing trip was a success, as you can tell by how I smelled right now.
Although this mistake may seem obvious, writers often mix tenses within sentences like this. They mistakenly assume that since the fishing trip occurred last night, so did the smell. The sentence should be rewritten as follows:
Last night's fishing trip was a success, as you can tell by how I smell right now.
Try one more example:
Every time I watch video clips of the day the Titanic sunk, I got chills.
The last verb in this sentence ("got") should not be in past tense. Sometimes writers assume that past events, including the sinking of the Titanic, mean that all verbs used to discuss them should be in past tense. However, even though the Titanic sunk a long time ago, this writer's "chills" occur in the present. The following revision corrects the problem:
Every time I watch video clips of the day the Titanic sunk, I get chills.
Many English verbs don't follow the standard pattern of verb formation. They are called irregular verbs. Following are some examples of commonly-used irregular verbs:
The preceding list does not include all irregular verbs; there are others that don't change form to express a change in tense in the same way as regular verbs. The past-tense form of these verbs does not end with "ed".
EXAMPLEThe regular verb "ask" becomes "asked" in past tense. However, "choose" becomes "chose", "make" becomes "made", and "write" becomes "wrote", etc.
The words listed in the preceding example follow different rules for tense changes. Those rules (and exceptions to those rules) are beyond the scope of this tutorial. However, here's one general principle to observe regarding verb tense and irregular verbs: trust your ears. When reviewing what you've written, read out loud when you can. Something like "choosed" should sound wrong to you.
Source: Adapted from Sophia Instructor Gavin McCall