Learn Finnish: Lyhytkarvaisella kissalla on valkoiset tassut ja musta turkki. - The short-haired cat has white paws and a black coat.

It combines the adjective modifier lyhyt (short), the noun stem karva (hair/fur), and the suffix -inen, which turns it into a property adjective. Notice that the first part (lyhyt) stays in its basic nominative form rather than taking a genitive form.

Why is the adjective in the form lyhytkarvaisella instead of its dictionary form?

It modifies the noun kissalla, so it has to match its case. The sentence uses the Finnish "have" structure (-lla on, literally "on something is"), which puts the owner in the adessive case (-lla). When adding case endings to -inen adjectives, the stem always changes to -ise-, making it lyhytkarvaise- + -lla.

Why are valkoiset tassut and musta turkki in the basic nominative case instead of the partitive?

In a "have" construction, the things being owned are grammatically the subjects of the sentence. Because a coat and paws are countable and we are talking about complete wholes (the cat's entire coat, and a full set of paws), they take the nominative case. You would only use the partitive here for uncountable masses or incomplete quantities.

What is the difference between karva (inside the compound word) and turkki?