Learn Hardcore Finnish: Hän on hyvin ystävällinen ihminen.

Because it’s the first word of the sentence. In Finnish, only the very first word of any sentence gets a capital letter. The pronoun hän itself is not capitalized when it appears in the middle of a sentence.

Does Hän specify gender?

No. Finnish hän is completely gender-neutral. It can mean “he,” “she,” or “they” (singular) depending on context. There is no separate “he” or “she” pronoun in Finnish.

What is on doing in this sentence?

On is the third person singular present form of the verb olla (“to be”). So Hän on simply means “He/she/they is.”

What does hyvin mean here? Can I use other words instead?

Hyvin is an adverb meaning “very” or “well.” Here it intensifies the adjective ystävällinen, giving “very friendly.” You can also use other intensifiers like todella (“really”), erittäin (“extremely”), or kovin (“quite”).

Why is hyvin placed before ystävällinen?

In Finnish, adverbs that modify adjectives normally come immediately before the adjective. So you say hyvin ystävällinen (“very friendly”) rather than ystävällinen hyvin.

Why does ystävällinen end in -nen? How do adjectives agree with nouns?

Many Finnish adjectives end in -nen. Adjectives must agree in case and number with the noun they describe. Here ihminen (“person”) is in the nominative singular, so the adjective also takes its nominative singular form ystävällinen.

Why is there no article (“a” or “the”) before ihminen?

Finnish does not use articles like English “a” or “the.” Whether ihminen is “a person” or “the person” is understood from context.

Can I switch hyvin to something else or change the word order?

Yes. You could say Hän on todella ystävällinen ihminen (“He/she is a really friendly person”) or Hän on erittäin ystävällinen ihminen. Finnish word order is fairly flexible, but putting the adverb directly before the adjective and the adjective before the noun is the most natural for this kind of statement.