In the book ” Aristotle and Dante Discover the Secrets of the Universe” the author writes the following sentence.
“That’s when I heard his voice, kind of squeaky(…)”
Is it correct to say “that is” in in the same sentence of a verb used in the past tense?
The use of both tenses confuses me, can anyone explain what rule that is?
It is correct and there’s no rule in English saying otherwise. Here’s an article that will explain it better: https://www.veritasprep.com/blog/2017/08/multiple-tenses-gmat-sentence/. The main takeaway from it is:
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 use multiple tenses in the same sentence.
Keeping that in mind, all of the following are correct:
- That is when I heard his voice
- That is when I hear his voice
- That is when I will hear his voice