Learn Icelandic: Ég labbaði heim í gær.

The dictionary form of the verb is labba. Because it belongs to Group 1 of regular verbs, we make the past tense for "I" (ég) by taking off the final -a and adding -aði. That gives us labbaði (I walked).

I learned the word ganga for "to walk". Why is labba used here?

Both mean "to walk"! Ganga is the standard word, but it has irregular past tense forms. Labba is a slightly more casual, everyday word for walking or strolling. It is also completely regular, making it a great word to practice your new -aði past tense endings!

I've seen the word heima for "home" before. Why does this sentence use heim?

In Icelandic, words for places often change depending on whether you are at the place or moving to it. You use heima when you are already at home (location). You use heim when you are going or moving to your home (direction). Because you are walking there in this sentence, we must use heim.

Does í gær literally translate to "in yesterday"?