Questions & Answers about Bros og sýn mér bókina!
How do we form the command words bros and sýn?
To give a command to one person, you generally take the infinitive (dictionary) form of the verb and drop the final -a. The infinitive verbs here are brosa (to smile) and sýna (to show), so dropping the -a gives us the base commands bros and sýn.
I often hear commands with endings like -du or -tu. Why don't bros and sýn have them?
You will very often hear these commands as brostu and sýndu! In spoken Icelandic, it is much more common to attach the word for "you" (þú) to the end of the command, which morphs into -du, -tu, or -ðu. The short forms bros and sýn used here are the basic, strict command forms. They are completely correct but can sound a bit more formal, written, or poetic than the versions with endings.
Why does the sentence use mér instead of mig for "me"?
The verb sýna (to show) gives us a classic double-object situation. The person you are showing something to (the indirect object) is put in the dative case. So, the pronoun ég (I) becomes mér. The thing actually being shown goes in the accusative case.
Why is it bókina and not just bókin?