Learn Swedish: Den sura mjölken kommer han att kasta. - The sour milk, he will throw away.

This is called topicalization. By putting the object (Den sura mjölken) first, we are emphasizing it. It is like saying As for the sour milk, he will throw it away in English. Swedish does this often to create contrast or focus on a specific thing.

Why does it say kommer han instead of han kommer?

Because of the V2 (verb-second) rule! In a Swedish main clause, the conjugated verb (the one showing the tense, which is kommer here) must be the second block of information. Since the object (Den sura mjölken) took the first spot, the verb must come next. This pushes the subject (han) to the third spot, creating OVS (Object-Verb-Subject) word order.

Why is the adjective sura instead of sur, even though mjölk is an en-word?

Because the noun is definite. When you describe a specific, definite noun with an adjective, Swedish uses the double definite form. You need the independent article (Den), the adjective with an -a at the end (sura), and the noun in its definite form (mjölken).

Can I drop the att in kommer han att kasta?