Questions & Answers about Það gleður mig að þú viljir læra meira íslensku.
Here það is a dummy subject, much like English it in It makes me happy that...
The real content is in the clause að þú viljir læra meira íslensku, but Icelandic often puts that heavier clause later and uses það in the subject position first.
So structurally, this is very similar to:
- It pleases me that...
- Það gleður mig að...
You can also say Að þú viljir læra meira íslensku gleður mig, but that sounds more formal or literary.
Because the verb gleðja takes a direct object in the accusative.
So:
- gleðja einhvern = to make someone glad
- mig = me in the accusative
That means mig is correct here.
This is one of those things you simply learn with the verb:
- Það gleður mig = it gladdens me / it makes me happy
A learner may expect mér because many Icelandic feeling-expressions use the dative, but gleðja is not one of them.