So "synes" breaks the -(e)r rule of present tense verbs? What is its infinitive?
The infinitive is also 'synes'.
why not 'tenker'? it was marked as incorrect for me 'De tenker byen er pen'
"Synes" is used for personal opinions and "tror" is used for assumptions of truth, regardless of opinion.
Thanks Luke. What about 'tenke' though? Is that not also 'think'?
You would use 'tenke' while having your head in the clouds and thinkin about e.g. your SO :) It refers to literal process of thinking.
It's also to "think," but in a very, very literal sense (you don't use it for opinions or assumptions of truth).
what about de mener byen er vakker?
Maybe a stupid question but why is their no 'e' on 'pen'. Are not the subjects plural or is it singular because of 'the city' being single?
Yes, because 'pen' refers to 'byen' it is singular, regardless of how many people think so.