Learn Finnish: Pakkaammeko ne erikseen noihin laatikoihin? - Do we pack them separately into those boxes?

The base word is tuo, which means 'that'. Because we are talking about plural objects ('those'), the stem becomes noi-. We are packing things into the boxes, so we need the illative case ('into'). Adding the plural illative ending -hin to the stem gives us noihin.

Why does laatikoihin (into boxes) have only one 'k', while the basic word laatikko has two?

This is due to consonant gradation. When we add the plural marker -i- and the illative ending -hin, the double kk in laatikko weakens to a single k. Notice how the pronoun noihin and the noun laatikoihin perfectly match in their plural illative endings!

How is the word pakkaammeko built from the dictionary form?

The dictionary form is pakata (to pack). For this verb type, the single k strengthens to a double kk when conjugated. So, 'we pack' is pakkaamme. To turn it into a yes/no question, we simply attach the question particle -ko to the end, creating pakkaammeko.

The word ne usually means 'they', but here it's translated as 'them'. Why don't we use the partitive case niitä?