In this sentence 'The price was so/just expensive?', the answer based on the key is 'so' not just. However, just can also be used for emphasis. So why here it's not possible? To me both words are OK. I heard it from one of my colleagues that we use 'just' to denote something positive rather than negative. But I couldn't find it in the grammar book. Is she also right?
Thanks a lot.
Being a non-native teacher, I'm so thrilled being in such a superb forum.
In BrE, you can use just + non-gradable adjective for emphasis- it was just superb/appalling, so it doesn't have to be positive.