"The machines are new!"
Translation:Ty stroje jsou nové!
Why is "Stroji jsou nové!" incorrect if the translation is "The machines are new'. Why do you need Ty?
Ty in this case represents 'the/those.' You may wish to consult Tips&Notes sections for more info on Czech grammar.
Moreover, nominative plural is stroje not stroji.
I do not agree. I am native speaker and in Czech - there is no need to use "ty" every time when there is "the" in English. So "Stroje jsou nové!" should be also accepted. It is needed only when you want to put stress on the machines, but you might want have more stress on the fact that it is new.
THANK YOU! I've been told this by many native speakers many times over the past two years living in Prague. I think this course has a lot of things like this where we need more natives to review. It's far too rigid.
Be aware it will not sound strange only in specific situations and be aware that we do allow this where we believe it makes sense. In sentences like "The cat can see the dog." the demonstrative pronouns are not required. It is always possible the number of these cases will be expanded.