Questions & Answers about Bíddu hér í smástund.
Because bíddu is the imperative singular of bíða (to wait).
In other words:
- bíða = to wait
- bíddu = wait! / wait here! when speaking to one person
So the sentence uses the normal command form, not the infinitive.
Bíddu is for one person.
If you are telling more than one person to wait, you would say:
- Bíðið hér í smástund.
So the sentence as written is singular: you are addressing one listener.
In Icelandic, the subject pronoun is usually left out in commands, just as it often is in English:
- Wait here.
not usually You wait here.
So bíddu already includes the idea of you. Adding þú is possible for emphasis, but it is not the normal neutral way to give a simple instruction.