Learn Dutch: De eend vliegt met de zwerm mee. - The duck flies along with the flock.

The main verb is the separable verb meevliegen (to fly along / to accompany). While English simply says 'flies with', Dutch uses the mee- prefix to emphasize participating or joining in. The preposition met (with) is then used to introduce the group they are joining (de zwerm).

Why is the prefix mee placed at the very end of the sentence?

In a main clause, the conjugated part of a separable verb (vliegt) takes the second position, while the separable prefix (mee) moves to the very end of the clause. This means it wraps around the prepositional phrase met de zwerm.

Does zwerm apply to any group of animals?

No, a zwerm (swarm or flock) is specifically used for flying creatures like birds or insects. For grazing land animals you would use a kudde (herd), and for wolves or dogs a roedel (pack).

How would we apply the lesson topic of indefinite numbers (like tientallen) to this sentence?

You could swap out the specific collective noun zwerm for an indefinite aggregate like tientallen (dozens) or honderden (hundreds). For example, De eend vliegt met tientallen andere vogels mee means 'The duck flies along with dozens of other birds'.