viikkoa

In a sentence

• Olen ollut lomalla kaksi viikkoa.

  I have been on vacation for two weeks.

  The word 'viikkoa' here is in the partitive case, indicating a duration of time.

• Näemme taas viikon päästä.

  We will see each other again in a week.

  The word 'viikon' here is in the genitive case, indicating a time reference.

• Viikko alkoi sateisena.

  The week started with rain.

  The word 'viikko' here is in the nominative form, acting as the subject of the sentence.

• Hän viettää lomaa kolme viikkoa.

  He is spending three weeks on vacation.

  Here, 'viikkoa' is in the partitive case, which is used because 'kolme' (three) requires the following noun to appear in that case to indicate an amount or time span.

• Ensimmäiset viikkoa opiskelussa olivat haastavia.

  The first weeks of studies were challenging.

  In this sentence, 'viikkoa' might appear due to the influence of colloquial usage; however, 'viikot' or another form could correctly fit depending on the structure required.

• Viikkoa ennen juhlaa hän alkoi valmistella ohjelmaa.

  A week before the party, he started preparing the program.

  Here, 'viikkoa' is in the partitive case, used commonly after words or expressions indicating temporal proximity, like 'a week before'.