Learn Finnish: Hän on etäisehkö pikkuserkku, joten en tunne häntä. - He is a rather distant second cousin, so I do not know him.

The base adjective is etäinen (distant). Words ending in -nen change this ending to -se- to form their inflectional stem. To this stem, we add the new moderated degree suffix -hkö. We use the front-vowel version (-hkö rather than -hko) because the base word contains the front vowels ä and e.

Is pikku a normal adjective in pikkuserkku?

Pikkuserkku translates to second cousin, though it literally looks like little cousin. The word pikku is a special, undeclinable adjective. It is mostly used as a prefix in compound words and never changes its form, regardless of what case the main noun takes.

Why is the object häntä in the partitive case?

The verb tuntea (to know someone) takes an object. While an affirmative sentence might use the accusative case, this is a negative sentence (en tunne). A strict rule in Finnish grammar is that the object of a negative action must always be in the partitive case, so hän becomes häntä.

Could I use niin instead of joten to mean so?

While niin is often used in spoken Finnish for so, joten is the correct standard conjunction here. Joten specifically means therefore or as a result, connecting two clauses to show a direct logical consequence.