Learn Hardcore Icelandic: Ég slekk strax á vekjaraklukkunni. - I immediately turn off the alarm clock.

The verb slökkva is always used with the preposition á plus a dative object when you switch something off. You never say slökkva vekjaraklukkuna; you say slökkva á vekjaraklukkunni.

What case is vekjaraklukkunni, and how is it formed?

Vekjaraklukkunni is the definite dative singular form of vekjaraklukka (“an alarm clock”).
Formation steps:

Start with vekjaraklukka (indefinite nominative/dative).
Make it definite → vekjaraklukkan (nom.), vekjaraklukkuna (acc.), vekjaraklukkunnar (gen.), vekjaraklukkunni (dat.).

How are compound nouns like vekjaraklukka constructed in Icelandic?

Icelandic compounds often use the genitive singular of the first noun plus a linking vowel (commonly a). Here:

vekjari (nom.) → vekjara (gen.)
- klukka (“clock”)
  = vekjaraklukka (“alarm clock”).

What does strax mean, and where can it be placed in the sentence?

Strax means “immediately” or “right away.” Common positions:

After the finite verb: Ég slekk strax á vekjaraklukkunni.
After the object: Ég slekk á vekjaraklukkunni strax.
Fronted for emphasis: Strax slekk ég á vekjaraklukkunni.

Can you omit the pronoun ég here?

Yes. Verbs in Icelandic are conjugated for person, so slekk already tells you it’s “I.” In informal speech you can say slekk strax á vekjaraklukkunni, though in writing ég is often kept for clarity.

Is there another way to say “turn off the alarm clock” in Icelandic?

Yes. For example:

Ég slekk á vekjaranum strax. (using vekjarinn, “the alarm”)
Ég læt vekjaraklukkuna þegja. (“I make the alarm clock be silent”) – a more idiomatic variant but less common.