Could it also be "Ona nie widzi tego"? I don't get the word order in polish.
I believe so, the word order can change based on what part of the sentence is being emphasized, which is why it's important to look at the cases of each word.
So, would "ona nie widzi tego" empasize "widzi", or another word?
Usually the emphasized word comes last as if you'd like to keep your interlocutor in suspence or sth. :D So in your case "tego/this" is being emphasized.
Why can't it be "She doesn't see him"?
No, that's "Ona go nie widzi" (or possibly "Ona jego nie widzi", but using 'jego' gives a rather strange emphasis).
Can't tego mean "this" in this case? I'm pretty sure I've translated it that way in previous exercises
Yes it can, it should have worked.
Could it also be "Ona to nie widzi"
Any real difference?
Actually yes, tego is the genitive form of to so it shows that it's the direct object of widzi when wifi is negated. By only using to, it doesn't show that it's the direct object of widzi.
I just double checked--isn't "tego" the genitive form rather than the accus? So I guess it's tego because there's a negation
Yeah, I brain farted there
Is "tego" used because of the negation requiring a genitive form?
Yup. Negation of a verb that took Accusative before. Other cases don't change when negated.
I used tego...and it said I was wrong?
Sorry....I used him as translation for tego and it was wrong. Why?
Tego (gen.) is this or it.
Him would be jego (which can sometimes be shortened to go) - see Jellei's comment ca. halfway up this page.