Past tense and present tense confusion

Question

I was reading through an entry earlier and I noticed I mixed past tense and present tense in writing:

"Terri looked over the clouds as the plane carried her weightlessly. She was so glad to get away from all of her problems, she feared she might extend her holiday. She sipped sweet brandy as she watched a rather monotonous show on the television. Tired, she leans back in her plush seat, eyelids falling as the dull words of the announcer slowly disintegrates into the darkness."

I've never really studied English, I don't know when it's okay to mix the two tenses. In this case, it's clearly present tense in a past tense paragraph, so it must be wrong?

Answer 1

Yes, it's wrong to mix tenses ...

Tense consistency is desirable in any kind of expository writing. Changing tense suddenly can confuse the reader, who's got used to reading in one tense and now feels wrong-footed.

... unless there's a good reason to do so.

Many grammatical rules have exceptions, and this one is no exception (pun intended). Sometimes, tense inconsistency might be exactly what you want to do in order to achieve a certain effect.

I can't think of a good reason to change mid-paragraph (although I'm sure such a reason exists somewhere), but I know one book written mostly in the past tense except for all the scenes with a particular point-of-view character being written in the present tense. This helped to build a sense of creepy foreboding in these scenes, making it feel more like a horror story than most of the book, and it also fit with the character's general lack of forward-thinkingness - just as his mind was fixated on living in the moment, so the scenes featuring him were fixated on the present.

Answer 2

In this particular paragraph, it does seem a little off. But I do not think changing tenses mid-paragraph is unconditionally wrong.