It depends what you are saying. For example, it's correct to say this: "Walk in a straight line unless otherwise directed". It is not correct to say something weird like "Well call me unless otherwise you don't want to" or something. But it can be done.
This is not correct grammar. The correct way to say this would be "Unless we hurry, we will be late for the show." You would not say anything if you were not going to be late.
Never, unless you use unproper grammar.
Unless otherwise unless=unless Otherwise=reverse of what it is (reverse case from its original case) so if we are talking like, DON'T GO THERE UNLESS OTHERWISE it means DON'T GO THERE UNLESS OTHERWISE(IT IS REQUIRED TO DO)
It is correct to say "on the planet." This is because we live on the surface of the planet, not inside of it.
No They are not . They have confirmed they are just friends. Unless they say otherwise . No.
"And so are you" is grammatically correct used in an otherwise correctly structured sentence.
Not unless you add the word "the" between "for" and "last."
No it is not unless it is in the context of an indirect object where "to" or "for" plus the above phrase is grammatically correct. In addition, it is better to say "my partner and I" although that can lead to rather convoluted sentences.
The correct spelling is "otherwise" (in an alternate circumstance).
Unless "the weekends" is a place you can go to, then no, it isn't correct. It is best to say "On the weekends" if you mean the days Saturday & Sunday.
Yes, as an incomplete sentence, followed by a prepositional phrase. Otherwise, "Who did you expect?" is standard.
Unless there's something in it for THEM - no, never.When it suits them. Not otherwise. See the link below.