Let us start with an example:
This sentence can mean two different things in Danish. It can mean:
Or it can mean:
'Tror' = an estimate of truth
When we say 'tror', we give an estimate of truth. We talk about something that has a certain probability. And it is something that can be checked in reality. That is, we can investigate whether it is right or wrong.
(I think the chef has put salt in the food.)
'Synes' = a personal opinion
When we say 'synes', we talk about a personal opinion or experience.
Here I express something that is 100% my own opinion. After all, it is perfectly possible that the friends I watched the film with thought it was bad.
Here I express an assumption that the film will be good, but I have not seen it yet.
'Tror' can be an assumption about the future
We can also say 'tror' when making an assumption about the future. Because we cannot say anything for certain about the future. But we can have it verified - in the future!
(I think Argentina will win the match against Brazil on Friday.)
Here I express an assumption about how the match will end, even though I don't know anything about it yet. But on Friday, I will be able to confirm or deny my theory.
Test yourself
Here you can test your knowledge of 'tror' and 'synes':