Learn Hardcore Icelandic: Ég borðaði morgunmat klukkan sjö í morgun.

Icelandic verbs are indeed conjugated for person and number, but in most neutral statements you still include the subject pronoun. It avoids ambiguity (some verb forms can look alike across persons), helps with emphasis/contrast, and follows the general pattern of Modern Icelandic. Dropping Ég here (e.g. just saying “Borðaði morgunmat…”) would sound odd or incomplete.

What is borðaði, and how does it relate to the infinitive form of the verb?

borðaði is the past‐tense (preterite) form of borða (to eat) for first person singular. It’s a weak verb in the –a class, which in the past tense adds the dental suffix –aði. So
• infinitive: borða
• ég-form past: borðaði

What case is morgunmat in, and why doesn’t it end in –ur like the dictionary form?

morgunmat is in the accusative singular because it’s the direct object (“I ate breakfast”). The dictionary (nominative) form is morgunmatur (“a breakfast”). In the accusative you drop the –ur ending on this strong masculine noun, yielding morgunmat.

Why do we say klukkan sjö to mean “at seven o’clock” instead of just sjö?

When telling exact time you use the definite form of klukka (clock) plus the numeral: klukkan sjö literally “the clock [is] seven.” Without klukkan you’d just say the number, which sounds incomplete if you mean “at exactly seven.” For approximate times you could say um sjö (“around seven”), but for precision you need klukkan.

Why is klukkan in the definite form here?

Time expressions in Icelandic normally take the definite article on klukka. Grammatically, you’re referring to “the clock at seven,” so you use the feminine noun klukka plus its definite accusative ending –n → klukkan.

Why does morgun appear twice—in morgunmat and in í morgun—and do they mean the same thing?

They share the root morgun (“morning”) but function differently.
• morgunmat is a compound noun meaning “morning‐meal” (breakfast).
• í morgun is an adverbial phrase (“this morning”) formed with the preposition í plus the accusative morgun. They refer to the same general time of day, but one names a meal and the other marks when the action happened.

Can we move í morgun or klukkan sjö to a different position in the sentence?

Yes—but you must respect Icelandic’s V2 (verb‐second) rule. For example:
• Í morgun borðaði ég morgunmat klukkan sjö. (Time first, verb second.)
You cannot say Ég í morgun borðaði… because the finite verb must occupy the second position in a main clause.

Could we omit klukkan and simply say sjö í morgun?

If you drop klukkan, it sounds like you’re giving an approximate time um sjö í morgun (“around seven this morning”). For an exact hour you normally include klukkan. Saying sjö í morgun without any preposition or klukkan would be ungrammatical in standard Icelandic.