In the following sentence I'd like to convey that "I don't know what space an item currently takes up or what space it will take up at some undefined future time". I contracted the sentence using parentheses* to read:
I don't know what space it (will) take up.
My memory of primary school tells me that a sentence should still make sense if the bracketed section was removed, meaning I would have to conjugate "take" as if it were present tense. When I read this, however, it sounds wrong.
I don't know what space it (will) takes up.
Should I always favour the way the complete sentence reads, in this case, conjugating for the future tense?
*brackets [BrE] but my programmer mind is often tuned to AmE alternatives.