Learn Finnish: Otsikko on uusi. - The headline is new.

You simply change the verb on (is) to its past tense form oli (was), making the sentence Otsikko oli uusi. The subject otsikko and the adjective uusi stay in their basic nominative forms.

The current lesson is about consonant gradation. Why isn't there any consonant gradation in otsikko?

Consonant gradation happens when we add endings that close a syllable. Because otsikko is the subject of the sentence, it is in its basic dictionary form without any extra endings. Therefore, it keeps its strong kk. If you added an ending, like the plural -t for "headlines", it would weaken to a single k to become otsikot.

Does the word otsikko come from another Finnish word?

Yes! It is derived from the word otsa, which means "forehead". The suffix -ikko is used to create a noun representing a group or a specific entity. So otsikko is literally the thing at the "head" or top of the page, which perfectly translates to "headline" or "title".

I remember the word uusi behaves a bit weirdly when endings are added. What is its stem?