Learn Hardcore Icelandic: Ég kem í afmælið þitt í næsta mánuði.

Icelandic often uses the present tense to refer to the near or planned future when there’s a time expression. Here, í næsta mánuði makes it clear it’s future. You could also say:

Ég mun koma í afmælið þitt í næsta mánuði (I will come; neutral future or a promise)
Ég ætla að koma í afmælið þitt í næsta mánuði (I intend/plan to come) All are correct; the simple present is very natural and common.

Why is the preposition í used with afmæli? Could I use á?

With afmæli (birthday/birthday party), Icelandic idiomatically uses í for both motion to and location at the event:

Ég kem í afmælið = I am coming to the birthday (party).
Ég er í afmæli = I’m at a birthday (party).

Be careful: að eiga afmæli with á means “to have a birthday,” e.g., Ég á afmæli í dag (It’s my birthday today). So avoid á afmæli when you mean attending a party.

What does the -ið on afmælið do?

It’s the definite article suffixed to the noun: afmæli (a birthday/party) → afmælið (the birthday/party). Icelandic usually attaches “the” to the end of the noun. Because you’re talking about a specific event (your birthday), definiteness fits naturally.

Why is the possessive after the noun (afmælið þitt) and is þitt afmæli also possible?

Both are possible:

afmælið þitt (postposed possessive) is very common and clearly definite/specific.
þitt afmæli (preposed) is also correct and can put a bit more emphasis on “your.” Do not combine preposed possessive with the definite suffix: avoid þitt afmælið.

Why is it í afmælið (accusative) but í næsta mánuði (dative)?

The preposition í takes different cases depending on meaning:

Motion into/onto something → accusative: Ég kem í afmælið (I’m coming into/to the event).
Location/time in/at → dative: í næsta mánuði (in next month). So you see both cases in one sentence for two different functions (goal vs. time).

Why is it næsta mánuði and not næstu mánuði?

Mánuður is masculine. In í næsta mánuði, mánuði is dative singular masculine, and the adjective næstur agrees: dative singular masculine weak form næsta. Næstu would be feminine singular dative or plural and doesn’t match mánuði here.

Could I leave out í before the time expression?

Most natural is í næsta mánuði. You will also hear næsta mánuð (accusative) to mean “next month” in general time reference, especially with verbs like “be, stay, do” across a span (e.g., Ég er upptekinn næsta mánuð). For learners, stick with í næsta mánuði when you mean “in next month.”

Can I change the word order, e.g., put the time first?

Yes. Icelandic is a V2 language, so the finite verb stays in second position:

Í næsta mánuði kem ég í afmælið þitt.
Ég kem í afmælið þitt í næsta mánuði. Both are fine; fronting the time phrase adds emphasis to “next month.”

Can I drop the subject pronoun (Ég) like in some other languages?

No. Icelandic is not a pro‑drop language, so you normally keep the subject pronoun: Ég kem …, not just Kem … (except in imperatives or special styles).

What’s the difference between í afmælið þitt, í afmæli, and þitt afmæli?

í afmælið þitt = to your specific birthday (party).
í afmæli = to a birthday (party), not specifying whose.
þitt afmæli is just the noun phrase “your birthday”; to say “to your birthday,” either í afmælið þitt (very common) or í þitt afmæli (also possible, less common).

Could I say something more like “attend/show up” instead of “come”?

Yes:

Ég mæti í afmælið þitt í næsta mánuði. (I’ll attend/show up…)
Ég kíki í afmælið þitt… (I’ll drop by/pop in…; more casual) Koma is the most neutral and widely used.

Does afmæli mean the party or the day itself?

It can mean both, but in the pattern í afmæli it almost always means the party. If you mean the calendar day, you can say:

á afmælisdaginn þinn (on your birthday [day])
Ég á afmæli (It’s my birthday)

How do you conjugate koma (to come) in the present?

ég kem
þú kemur
hann/hún/það kemur
við komum
þið komið
þeir/þær/þau koma

Any quick pronunciation tips for tricky letters here?

þ in þitt = unvoiced th, like English “thing.”
ð in mánuði/afmælið = voiced th, like “this” (often softer between vowels).
á = like the vowel in “cow.”
æ in næsta = like “eye.”
k in kem is palatalized before front vowels, sounding a bit like “kyem.”