Learn Hardcore Icelandic: Gefðu mér vatn.

In Icelandic imperatives the subject pronoun þú is omitted because the verb ending -ðu (for second person singular) already indicates the subject. So gefðu on its own means ‘you give’.

How is the imperative gefðu formed from the infinitive að gefa?

To make the 2nd person singular imperative of gefa, drop the infinitive -a to get the stem gef-, then add -ðu. Hence gef- + ðu = gefðu.

Why is mér used instead of mig in this sentence?

The verb gefa (‘to give’) is ditransitive: it takes a dative object for the recipient and an accusative object for the thing given. mér is the dative form of ég, so it marks the person receiving the water (‘to me’).

Why is there no preposition (like “til”) before mér to indicate “to me”?

In Icelandic, verbs like gefa govern the dative case directly for the indirect object, so you don’t need a preposition. The dative form mér inherently means “to me.”

What case is vatn in, and why does it look like the nominative?