Learn Swedish: Man svävar vanligtvis högt över landskapet. - You usually float high above the landscape.

The word vanligtvis (usually) is built from the adjective vanlig (usual). First, it takes the neuter -t ending to become vanligt, and then the suffix -vis is added. This suffix works a lot like the English ending "-ly" to turn adjectives into adverbs that describe the whole sentence.

Why is vanligtvis placed right after the verb svävar?

Because vanligtvis is a sentence adverb. In a standard Swedish main clause, the rule is that sentence adverbs come immediately after the first verb. Here, that puts it right after svävar.

Why does the Swedish sentence use man when the English translation says "You"?

The word man is an indefinite pronoun, much like the English word "one" (as in "one usually floats"). While English speakers frequently use a general "you" in these situations, Swedish prefers man when stating a general fact or experience that applies to anyone, rather than speaking directly to a specific person (du).

Why does the word for "high" end in a -t here (högt instead of hög)?

Because it describes how one floats (svävar), meaning it is acting as an adverb rather than describing a noun. In Swedish, you typically turn an adjective like hög into an adverb by adding a -t to the end, giving us högt.