Learn Icelandic: Við ætlum að flokka þessa poka núna. - We are going to sort these bags now.

Þessa is the accusative masculine plural form of þessi (this/these). We use the accusative case here because 'these bags' are the direct object being acted upon by the verb flokka (to sort). If 'these bags' were the subject of the sentence, you would use the nominative form þessir.

Wait, isn't poka a singular form? Why does it mean 'bags' here?

The word poki (bag) is a weak masculine noun. For these types of nouns, the singular accusative, dative, and genitive form is poka. However, the accusative plural is also poka! You can tell it means 'bags' (plural) in this sentence because it is paired with the plural demonstrative pronoun þessa.

How does ætlum að flokka translate to 'are going to sort'?

Icelandic doesn't have a dedicated future tense. Instead, it often uses the verb ætla (to intend / to plan) followed by að and the infinitive of the main verb to express what you 'are going to' do. So við ætlum að flokka literally translates to 'we intend to sort'.

Why does the pronoun þessa have to change based on the noun?