Learn Polish: Szef przydzielił nam po cztery zadania dziennie. - The boss allocated us four tasks each daily.

You might remember using the Locative case to say "each" when dealing with the number one, for example: po jednym zadaniu. However, for numbers 2 and above, the distributive po requires the Accusative case. Since zadanie is a neuter noun, the Accusative plural phrase for "four tasks" is simply cztery zadania.

Why do we use nam instead of nas in this sentence?

The verb przydzielić means "to allocate" or "to assign," and it requires the Dative case for the recipient of the action. Nam is the Dative form of my (we), literally meaning "to us." Using nas would be incorrect because that is the Accusative or Genitive form.

Since the work is done "daily," why is the verb przydzielił in the perfective aspect?

While the tasks themselves are repeated daily, the boss's action of establishing this new workload was a single, completed event in the past. Therefore, we use the perfective verb przydzielił for that one-time assignment, even though the resulting work is an ongoing, repeated habit.

Could I use the phrase na dzień instead of the adverb dziennie?

Yes, you could definitely say na dzień and the meaning would remain exactly the same. However, dziennie is an extremely common, concise, and natural-sounding adverb to express a rate of "per day," especially in workplace or statistical contexts.