Numbers 1 to 4 in the accusative (einn, tvo, þrjá)

In Icelandic, the numbers one through four change to match the gender and case of the noun they count. (Numbers five and up do not change for gender). When counting direct objects, use these accusative forms:

NumberMasculineFeminineNeuter
Oneeinneinaeitt
Twotvotværtvö
Threeþrjáþrjárþrjú
Fourfjórafjórarfjögur

Notice how the numbers match the gender of masculine and feminine objects:

I am buying one hot dog and one bag.
Ég kaupi eina pylsu og einn poka.
He eats two hamburgers and drinks three soft drinks.
Hann borðar tvo hamborgara og drekkur þrjá gosdrykki.
We have three pancakes but only two cookies.
Við eigum þrjár pönnukökur en bara tvær smákökur.

Here are the neuter forms in action:

The child gets two bread rolls and one biscuit.
Barnið fær tvö rúmstykki og eitt kex.

When listing multiple objects of different genders, make sure to match each number to its specific noun:

Do you see four strawberries and three mushrooms?
Sérð þú fjögur jarðarber og þrjá sveppi?
We are going to cook four potatoes, three mushrooms and one onion.
Við ætlum að elda fjórar kartöflur, þrjá sveppi og einn lauk.