Learn Icelandic: Að mala kaffibaunina vel er mikilvægt. - Grinding the coffee bean well is important.

It is in the neuter singular form because it describes the entire infinitival clause Að mala kaffibaunina vel. In Icelandic, whenever an action or an infinitive phrase acts as the syntactic subject of a sentence, the connected adjective must be neuter.

Is it natural to start a sentence with an Að infinitive phrase like this?

While grammatically correct and common in writing, it can sound a bit formal. In everyday speech, Icelanders usually prefer starting with the dummy subject það, changing the sentence to Það er mikilvægt að mala kaffibaunina vel.

Why is the object kaffibaunina in the accusative case here?

Even though the action Að mala is part of the subject phrase, it still functions as a verb that takes a direct object. Since you are grinding the bean, kaffibaunina takes the accusative case, which for a feminine definite noun ends in -ina.

Does the verb mala have any other common meanings?

Yes! While it means to grind things like coffee, spices, or grain, að mala is also the exact verb used to describe a cat purring.