x is a positive odd integer --> x + 2 is a positive odd integer

The trouble comes in negating each statement when finding the contrapositive

do i negate the statements to:

x is a NEGATIVE odd integer

x + 2 is a NEGATIVE odd integer

or

x is a positive EVEN integer

x + 2 is a positive EVEN integer

or

x is a NEGATIVE EVEN integer

x + 2 is a NEGATIVE EVEN integer

or (likely not but i just thought i'd ask) U = universe

x is a positive odd U-Z

x + 2 is a positive odd U-Z

I know that a statement has a truth value, but my prof and the text never went over what parts of a statement are eligible for negation. Is it right to say that the statements I have used as examples are in fact statements even though x is unknown, because they are quantified?

Am I correct to say that the quantification of these statements is implicit rather than explicit?

Argh this seems like a lot of questions, I'd really appreciate it someone could answer at least a few of them if answering them all is too laborious.

Thanks