hef

In a sentence

• Ég hef lesið þessa bók.

  I have read this book.

  Here 'hef' is part of the verb phrase 'hef lesið' (have read), which is the present perfect tense in Icelandic.

• Hef ég rétt fyrir mér?

  Am I correct?

  In this sentence, 'hef' is used in a question form, serving as the auxiliary verb in the present tense.

• Ég hef vana að lesa á kvöldin.

  I have a habit of reading in the evenings.

  Here 'hef' is used to express possession, particularly of a habit, and is accompanied by the noun 'vana' (habit).