This is the 1st most frequent Icelandic word.
og
"Og" means "and" in English.
Connects two actions (going to the store and buying bread) happening sequentially.
Ég fór í búðina og keypti brauð.
I went to the store and bought bread.
Connects two adjectives (beautiful and shiny) describing an object.
Þessi skartgripur er fallegur og skínandi.
This piece of jewelry is beautiful and shiny.
Connects two proper nouns (Jón and Sigríður) as a compound subject.