What would be the correct verb tense for the following statement?

I learned (past tense, correct) that HIV virus was a serious disease and currently there is no vaccine for it.

(a) I learned about this fact in the past. So the verb "to learn" is in the past tense.

(b) HIV was a serious disease but also is still a serious disease. So do I use was or is ?

(c) currently there is no vaccine, and the statement uses the adverb "currently". So should I use was or is?

  • "HIV virus was a serious disease" being in simple past means that it is not serious anymore.
    – user3169
    Nov 12, 2017 at 2:21
  • so should both verbs be in the present tense? I have been under the (incorrect?) impression that the tense in the "that" clause needs to be consistent with the main sentence.
    – B Chen
    Nov 12, 2017 at 2:29
  • In this example, it is the difference between when you learned it (in the past) and what you learned at that time. Meaning at the time you learned it, the information in the "that" clause was in the present.
    – user3169
    Nov 12, 2017 at 6:34
  • Another point would be that "HIV virus is a serious disease" is always true, unless it mutated into a non-dangerous virus. Even if a cure or vaccine is found, it will still be a serious/dangerous virus.
    – user3169
    Nov 12, 2017 at 6:38

1 Answer 1


Technically, if you're trying to say that HIV is still serious, you want to use is, not was. You don't have to match tense if you're referring to something that is currently factual. Likewise, you would also say there is no vaccine, because today there currently is no vaccine. There was no vaccine may also be a true statement, but it's not accurately describing what you're trying to say.

But there is also something to what you say about matching tenses. If you are writing an essay or even fiction where most of the events are generally past tense, then you can use was instead of is, even for current facts. It implies that your writing is describing events and facts that belong to a certain period of time. Vaccines or other treatments may have come and gone during that time, but it's not really your concern whether HIV is still a threat when the reader is currently reading your story/article, which could be five, twenty-five, or even a hundred years from now. Frankly it's not overly important to the rest of the story, which is why you can be vague about it. If the detail does happen to be important, you can say there had not been a vaccine instead of there was no vaccine if that more suitably describes the situation.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .