Learn Hardcore Dutch: Anna legt de grammatica aantrekkelijk uit. - Anna explains the grammar in an attractive way.

Uitleggen is a separable verb. In main clauses the prefix uit detaches and moves to the end. The remaining stem leg is conjugated (here as legt) and stays in second position after the subject.

Why is legt used instead of leg?

Dutch verbs in the present tense add -t for third person singular (he/she/it). Since Anna is third person singular, leg becomes legt.

Why is de used before grammatica?

Dutch has two article genders: common (with de) and neuter (with het). Grammatica is a common-gender noun, so it takes the article de.

What part of speech is aantrekkelijk, and why doesn’t it change form?

Here aantrekkelijk functions as an adverb, describing how she explains. Adverbs in Dutch remain in their base form and don’t inflect like adjectives do before nouns.

Why is the word order Subject–Verb–Object–Adverb–Prefix?

Dutch main clauses follow the V2 rule: the finite verb is in second position, then you place objects, adverbs, and finally any detached separable prefix. Hence:
Anna (S) – legt (V) – de grammatica (O) – aantrekkelijk (Adv) – uit (prefix).

What happens to the separable prefix uit in a subordinate clause?

In subordinate clauses the finite verb moves to the end and the separable prefix rejoins the stem. So you’d say:
Ik denk dat Anna de grammatica aantrekkelijk uitlegt.