Questions & Answers about Jag är desperat, men det gäller att vara lugn.
What exactly does det gäller att mean here, since gälla usually means 'to apply'?
While gälla on its own means 'to apply' or 'to be valid', the impersonal phrase det gäller att is a strong idiom. It means 'it is crucial to' or 'the most important thing right now is to'. It adds a sense of urgency that you wouldn't get from just saying det är viktigt att (it is important to).
Why is the adjective lugn in the common form instead of the neuter form lugnt, since the clause starts with det?
Great question! The det here is just a dummy subject for the phrase det gäller att. The adjective lugn describes the person who needs to be calm. Because the speaker (jag) is referring to themselves, they use the common en-word form lugn. If they were making a general statement about the situation being calm, they would use lugnt (like in det är lugnt).
Why doesn't the second clause specify who needs to be calm?
Because the subject is already established in the first clause (Jag är desperat), the second clause can use the infinitive phrase att vara lugn without repeating the subject. It is heavily implied from context that 'it is crucial for me to be calm'.
If I wanted to explicitly include the subject in the second clause, how would the grammar change?