Learn Finnish: Käyttäjä arvosteli valmistajan uuden tietokoneen. - The user reviewed the manufacturer's new computer.

The verb arvostella (to review or evaluate) takes a total object when an evaluation of a specific, whole item is completed. Since the user finished reviewing the entire computer, the object takes the accusative -n ending. If the reviewing process were still ongoing, you would use the partitive: Käyttäjä arvosteli tietokonetta.

Words like käyttäjä and valmistaja end in -ja/-jä. How does this differ from the -tava/-tävä endings we are learning in this lesson?

The -ja/-jä suffix attaches to a verb stem to create a noun for the person doing the action. For example, käyttää (to use) becomes käyttäjä (user). In contrast, the passive present participle -tava/-tävä ending creates an adjective describing something that can or must have the action done to it, like käytettävä (usable / to be used).

What is the dictionary form of arvosteli, and how is this past tense formed?

The dictionary form is arvostella (to review/evaluate), which is a Type 3 verb. To form the past tense, you take the consonant stem arvostel- and add the past tense marker -i, plus any personal ending. Since this is the third-person singular (he/she/it), there is no extra personal ending, leaving us with arvosteli.

In the phrase valmistajan uuden tietokoneen, are all three words in the genitive case?