Breakdown of Jag älskade inledningen, och det måste han också ha gjort.
jag
I
han
he
det
it (neuter)
och
and
Questions & Answers about Jag älskade inledningen, och det måste han också ha gjort.
What does det replace in this sentence, and why does it come right after och?
det is a pro-predicative, which is just a stand-in for the entire action from the first clause (älskade inledningen). Placing it at the front of the second clause creates a strong link to what was just said. Because det takes the first slot in this new main clause, the V2 rule kicks in, causing the verb and subject to swap places (måste han).
Why do we use ha gjort (have done) instead of repeating a form of älska (love)?
Just like English uses 'do so' or 'do it', Swedish uses göra det to avoid repeating a whole verb phrase. Because it follows the modal phrase måste ha (must have), göra takes its supine form, gjort. Together with the fronted det, it means 'have done so'.
Why is the adverb också in the middle of the phrase instead of at the end?
In a Swedish main clause, sentence adverbs like också usually go right after the finite verb and the subject. Since det pushed the finite verb (måste) to the second position and the subject (han) to the third, också naturally falls into the spot immediately following them, right before the remaining verbs (ha gjort).
How do we know måste is talking about a past deduction here?