Why not "I like it that you are here"? I got refused
mít rád (to like) vs být rád (be glad)
Can someone explain why there is a comma and why it goes after jsem rád? What's the rule for that?
These are two separate clauses and one of them is subordinate. Subordinate clauses are separated by a comma.
But haven't there been plenty of subordinate clauses before this lesson? I don't get why this is all the sudden appearing.
If they were, they had to be divided by a comma. You can point out some specific sentence and we might be able to explain. The earlier in the course, the simpler are the sentences.