Is It Incorrect to Use Multiple Verb Tenses in a Sentence

Some GMAT test-takers wonder whether it is grammatically correct to use multiple tenses in a single sentence. Today we will discuss the cases in which mixing verb tenses is acceptable and those in which this is not. The bottom line is this: there is no restriction on what tenses we can use and mix within a sentence, as long as  they are appropriate for the context. Take a look at this example sentence featuring multiple different verb tenses: I have heard that Mona left Manchester this morning, and has already arrived in London, where she will be for the next three weeks. Here, we have present perfect tense, simple past tense and simple future tense all in the same sentence. Were mixing different tenses, but they  all make sense together to create a logical sequence of events. The confusion over using multiple verb tenses in one sentence probably arises because we have heard that we need to maintain verb tense consistency. These two things are different. Tense Consistency We do not switch one tense to another unless the timing of the action demands that we do. We do not switch tenses when there is no time change for the actions. Pay particular attention to the unless clause in that description maintaining consistency of a single verb tense is not an absolute virtue! Verb tenses need to convey a logical timeline or sequence of events, so if there is a shift in the timeline of when events occurred, your job isnt to preserve verb tense consistency at all costs, but rather to mix verb tenses as necessary to tell a logical story of how and when things happened. Let’s take a look at some examples to understand this: Example 1: During the match, my dad stood up and waved at me. These two actions (stood and waved) happen at the same time and hence, need to have the same tense. This sentence could take place in the present or future tense too, but both verbs will still need to take on the same tense. For example: Example 2: During my matches, my dad stands up and waves at me. Example 3: During the match tomorrow, my dad will stand up and wave at me. On the other hand, a sentence such as Example 4: During the match, my dad stood up and waves at me. This sentence is grammatically incorrect. Since both actions (stood and waves) happen at the same time, we need them to be in the same tense, as shown in the variations of this sentence above. Consider this case, however: Example 5: My dad reached for the sandwich after he had already eaten a whole pizza. Here, the two actions (reached and eaten) happen at different times in the past, so we use both the simple past and past perfect tenses. The shift in tense is correct in this context, and that mixing tenses is necessary to convey a logical sequence of events. Takeaway: The tenses of verbs in a sentence must be consistent when the actions happen at the same time. When dealing with actions that occur at different points in time, however, we can and probably should use multiple tenses in the same sentence. Let’s look at an official GMAT question now to see how multiple tenses can be a part of the same sentence: For the farmer who takes care to keep them cool, providing them with high-energy feed, and milking them regularly, Holstein cows are producing an average of 2,275 gallons of milk each per year. (A) providing them with high-energy feed, and milking them regularly, Holstein cows are producing (B) providing them with high-energy feed, and milked regularly, the Holstein cow produces (C) provided with high-energy feed, and milking them regularly, Holstein cows are producing (D) provided with high-energy feed, and milked regularly, the Holstein cow produces (E) provided with high-energy feed, and milked regularly, Holstein cows will produce This is a very tricky question. Let’s first shortlist our options based on the obvious errors. The non-underlined part of the sentence uses the pronoun â€Å"them†Ã‚  to refer to the cows, so using â€Å"the Holstein cow† (singular) as the antecedent will be incorrect. The antecedent must be â€Å"Holstein cows† (plural) this means answer choices B and D are out. Also, we know for sure that â€Å"provide† and â€Å"milk† are parallel elements in the sentence, so they should take the same verb tense. Hence, answer choice C  is also out. Let’s look at  A now. If we assume this option is correct, â€Å"providing† and â€Å"milking† act as modifiers to â€Å"keep them cool†. That certainly does not make sense since â€Å"providing with high energy feed† and â€Å"milking regularly† are not ways of keeping cows cool. This means the correct answer is E, but we need to see how. For the farmer who takes care to keep them cool, provided with high-energy feed, and milked regularly, Holstein cows will produce an average of 2,275 gallons of milk each per year. Let’s break down the sentence: For the farmer who takes care to keep them cool, provided with high-energy feed, milked regularly, Holstein cows will produce an average of 2,275 gallons of milk each per year. Note that were mixing two different tenses here: For the farmer who takes care†¦ and cows will produce†¦. The word â€Å"takes† is the present tense while â€Å"will produce† is the future, but that does not make this sentence incorrect. The context of the author could very well justify the use of the future tense. Perhaps the farmers have obtained Holstein cows recently, and hence, will see the produce of 2,275 gallons in the future, only. A shift in the tense certainly doesn’t make the sentence incorrect. When youre presented with multiple verbs in various tenses in a problem, check to determine whether the verbs convey a logical sequence of events. If a sentence covers a broad timeline, your goal isnt to avoid mixing tenses, but instead to ensure that the tenses used properly reflect that timeline. Getting ready to take the GMAT? Check out one of our many  free GMAT resources  to get a jump start on your GMAT prep. And as always, be sure to follow us on  Facebook,  YouTube,  Google+, and  Twitter  for more helpful tips like this one! Karishma, a Computer Engineer with a keen interest in alternative Mathematical approaches, has mentored students in the continents of Asia, Europe and North America. She teaches the  GMAT  for Veritas Prep and regularly participates in content development projects such as  this blog! Note the proper use of mixed tenses there Karishmas many activities encompass the past, present, and future, so it takes multiple tenses to keep up with her.