Ég læt þig vita þegar ég kem heim.

I will let you know when I come home.

Breakdown of Ég læt þig vita þegar ég kem heim.

• ég: I
• þig: you
• þegar: when
• heim: home
• koma: to come
• láta vita: to let know

Questions & Answers about Ég læt þig vita þegar ég kem heim.

What does the structure læt … vita mean, and why is vita in the infinitive?

• láta is a causative verb: láta + [someone in the accusative] + [verb in the infinitive] = “make/let someone do something.”
• So Ég læt þig vita literally means “I cause you to know,” idiomatically “I’ll let you know.”
• The second verb (vita) stays in the bare infinitive (no að) after láta.
• Other examples: Ég læt hann bíða (I’ll make him wait), Hún lét þau koma (She let them come).

Why is it þig and not þér?

• þig is the accusative of þú and is used because láta takes the affected person in the accusative in this construction.
• Forms of þú: nominative þú, accusative þig, dative þér, genitive þín.
• So you say Ég læt þig vita, not “Ég læt þér vita.”

What form is læt and how does láta conjugate?

• læt is 1st person singular present indicative of láta.
• Present: ég læt, þú lætur, hann/hún/það lætur, við látum, þið látið, þeir/þær/þau láta.
• Past: ég lét, þú lést, hann lét, við létum, þið létuð, þeir létu.
• Past participle: látið. Note: þú lést can also mean “you passed away” from the middle verb látast; context disambiguates.

Why kem and not koma? What are the key forms of koma?

• kem is 1st person singular present of koma (to come).
• Present: ég kem, þú kemur, hann kemur, við komum, þið komið, þeir koma.
• Past: ég kom, þú komst, hann kom, við komum, þið komuð, þeir komu.

How is the future expressed here? Do you need munu?

• In time clauses (with þegar, “when”), Icelandic typically uses the present to talk about the future: þegar ég kem heim = “when I get home.”
• You normally do not use munu in the subordinate time clause. So avoid “þegar ég mun koma heim.”

Is Ég mun láta þig vita þegar ég kem heim also correct?

Yes. Using mun in the main clause is fine and makes the future time frame explicit. Just keep the time clause in the present: … þegar ég kem heim, not “mun koma.”

Can I say þegar að?

• In everyday speech many Icelanders say þegar að, but most style guides prefer plain þegar in formal writing.
• For learners, use þegar unless you’re matching informal speech.

Can I put the þegar-clause first?

Yes: Þegar ég kem heim, læt ég þig vita. Note the V2 rule in the main clause: after fronting the time clause, the finite verb (læt) comes before the subject (ég).

Why heim and not heima?

• heim is a directional adverb (“home-wards,” motion towards home): Ég kem heim (I’m coming home).
• heima means “at home” (location): Ég er heima (I’m at home). Use heim for movement, heima for location.

Can I specify whose home, like “to your place”?

Yes. Use heim til + genitive: Ég kem heim til þín (I’ll come to your place), … heim til mín (… to my place), … heim til hans/hennar (… to his/her place).

Is vita here the same verb as “to know”?

Yes. vita means “to know.” In this idiom láta (e-n) vita, it means “to let (someone) know.” Elsewhere you’ll see: Ég veit (I know), Veistu? (Do you know?), Við vitum (We know).

How do I make a request like “Let me know when you get home”?

• Singular imperative: Láttu mig vita þegar þú kemur heim.
• Plural/polite imperative: Látið mig vita þegar þið komið heim.
• Negative imperative: Ekki láta mig bíða (Don’t make me wait), or Láttu mig ekki bíða.

Could I use segja instead of láta vita?

• You can, but you must include what you will say: Ég segi þér það þegar ég kem heim (I’ll tell you that when I get home), or use a preposition: Ég segi þér frá þessu þegar ég kem heim (I’ll tell you about this …).
• láta (e-n) vita is the most idiomatic for “let someone know.”

Any punctuation tips with þegar here?

• With the time clause at the end, many writers omit the comma: Ég læt þig vita þegar ég kem heim.
• If you front the clause, add a comma after it: Þegar ég kem heim, læt ég þig vita. Both styles are acceptable; follow your target style guide.

How do I pronounce the tricky bits?

• Ég: often like “yeh/yei,” with a soft g (sometimes barely audible): [jɛː(ɣ)].
• læt: “light” with an open “eye” vowel: [lait].
• þig: voiceless th + short i + soft g: [θɪː(ɣ)].
• þegar: voiceless th, then “yeh/ar,” with a soft g: [ˈθjɛːɣar].
• kem: a palatal-ish k before e: roughly [cɛm] ~ “kyem.”
• heim: like English “hame”: [heiːm]. (Pronunciations vary slightly by region; these are approximations.)