Starting with a subordinate clause

A subordinate clause at the start of a sentence counts as the first element. The main clause that follows must keep its verb in second place, so the verb comes right after the subordinate clause and the subject follows the verb:

• Jag lagar mat när jag kommer hem. (I cook when I get home.)
• När jag kommer hem lagar jag mat. (When I get home, I cook.)

This works after när, om, eftersom, innan, medan and other subordinating words. You often get two verbs side by side across the clause border: Om det regnar stannar vi inne. (If it rains, we stay inside.)

Inside the subordinate clause itself the order is normal: subject, then verb (när jag kommer). A comma after the first clause is allowed but not required.