[userbinator]

ending periods actually have negative emotion in text vernacular now for younger audiences and should almost never be used in 1-1 messaging

That is extremely problematic, since I've already lost track of how many misparses (and resulting conflict over misunderstanding the meaning) have happened because of someone who wrote what should be multiple .-separated sentences as a single long and unpunctuated stream of text.

A memorable example: There is a huge difference between

    I didn't know that. He did it.

and

    I didn't know that he did it.

[abacadaba]

Correct Form: I didn't know that. He did it

[bccdee]

Once multiple sentences are on the table, it matters a lot less. The real significant line is between "zero periods; none needed" and "one redundant period at the end."

[adjkant]

OP here, I was very much referring to the last period, not periods in general.

[abacadaba]

I'm just glad I'm not the only one who's thought deeply about this :)

[bccdee]

Yeah, the original poster is grossly exaggerating. "Never use periods in instant messaging" is a really strange thing to say. However, it's true that the messages

> sure

and

> sure.

will be interpreted slightly differently from each other.