"Those are big machines."
Translation:To jsou velké mašiny.
The tips for the Plural lesson state that "ty" is used for masculine inanimate and it used the example of "ty stromy" (the trees, those trees). So, I have read all of the comments here and none of them explain why "ty" is incorrect. Please explain fully and please don't refer to a prior comment.
mašina is feminine
But here you do not have "ty mašiny" or "ty stromy" or whatever. You have "To jsou something". Where something can really be anything.
The TO is a part of the noun predicate construction, it is not an attribute of the noun. The translation of the TO JSOU is "these/those are", there is no gender involved.
"stroj" is the neutral, default, more common word.
"mašina" is colloquial, used less often, especially for generic machines. It's used a bit more for motorcycles, again- colloquially. Or it can mean a "mighty powerful machine", such as a brand new computer or an impressive strong machine.