"Fewer children are born each year"
Would it be wrong to translate as "...er født..." instead of "bliver født"
And for this particular sentence, how do i know tp use "bliver" instead of "er"
It would sound pretty odd, at least. "Er født" would refer to children that are already outside ("Hun er født i januar"), but in this sentence you want to talk about children that are in the act of being born. Or differently expressed, "at være født" is a state while "at blive født" is a process.
For a hint, you can try to insert 'being' into the sentence, and if it still means the same, you should use blive.
Men flere af dem bliver opkaldt Arya eller Sansa. http://www.dr.dk/Nyheder/Ligetil/Dagens_fokus/Kultur/2015/08/Flere_nyfoedte_faar_navne_fra_tv_serie.htm
Why do the verbs now end in t rather than es? And is there a way to tell which verbs end in which way?
They end with -t here because they're past participles now. At blive is the conjugated verb here. This variant functions likes in English: "Children are (being) born" - "Børn bliver født".
In the other, blive-less variant, the full verb is the conjugated verb, so it gets its proper passive (or reflexive) ending: "Døren åbnes" - "The door opens/is being opened."
Thank you for that, but i still have a question! in English, the door opens, and the door is being opened can have different meanings. Is this the same in Danish?
There is not a lot of difference between the two, but there are ways to make it clearer what's happening.
First off, a bit of explanation: the -es conjugation you learnt for the passive is historically (and probably more accurately) a reflexive suffix. "Døren åbnes" is derived from an earlier form of "Døren åbner sig" - "The door opens (itself)."
The bliver-form is more of a true passive. At blive is literally "to be/to become". So if you say "Døren bliver åbnet", you imply that there's someone who actively opens the door. You can get this meaning by going for active grammar, too, "Nogen åbner døren", but that's pretty un-Danish. Well, unless you care about that person. :)
less children are born every year should be accepted as less and fewer means the same thing
Well, "less" is commonly used instead of "fewer", but incorrectly so. "Less" should be used for uncountable nouns, "fewer" for countable nouns.
- little - less - least | much - more - most
- few - fewer - fewest | many - more - most
I tried with "Fewer children are being given birth every year." Refused.