Learn Icelandic: Ég kíkti á tölvupóstinn í gær.

Kíkja (to peek / to check) is a weak verb. Because the root ends with the voiceless consonant k, the past tense suffix hardens from a soft -di or -ði into the voiceless -ti to make it easier to pronounce together. Therefore, 'I checked' becomes ég kíkti.

Why do we need the word á here?

In Icelandic, the verb kíkja literally means 'to peek' or 'to look briefly'. Just like in English you peek 'at' something, in Icelandic you use the preposition á with this verb. So, kíkja á is the standard way to say 'to check' (such as checking an email, a phone, or a situation).

Why is the word for email written as tölvupóstinn here instead of tölvupósturinn?

Because of the preposition á. When á is used for an action directed at something, it forces the noun that follows into the accusative case. Tölvupóstur is a masculine noun, so its definite form drops the -ur ending and becomes tölvupóstinn (the email) when it is the object.

How do you break down the word tölvupóstur?

It is a compound of two everyday words: tölva (computer) and póstur (mail). So it literally translates to 'computer-mail'.