Ef snuðið dettur á gólfið, þvæ ég það strax.

Snuð is the basic noun, meaning pacifier.
Snuðið means the pacifier.

Icelandic usually adds the definite article to the end of the noun instead of using a separate word like English the.

• snuð = pacifier
• snuðið = the pacifier

In this sentence, the speaker is talking about a specific pacifier, so the definite form is used.

Dettur is the 3rd person singular present tense of the verb detta, meaning to fall.

So:

• ég dett = I fall
• þú dettur is not correct
• þú dettur/þú fellur? No — for detta, the correct form is:
  • ég dett
  • þú dettur
  • hann/hún/það dettur

Here the subject is snuðið, which is grammatically singular, so Icelandic uses the singular verb:

• snuðið dettur = the pacifier falls

This is a very common Icelandic pattern.

With prepositions like á, Icelandic often changes case depending on whether you mean:

• movement toward a place → accusative
• location in a place → dative

Here, the pacifier is falling onto the floor, so there is movement. That is why Icelandic uses:

• á gólfið = onto the floor

If it were already lying there, you would normally say:

• á gólfinu = on the floor

So the contrast is:

• Það dettur á gólfið. = It falls onto the floor.
• Það er á gólfinu. = It is on the floor.

This is because Icelandic is a verb-second language.

In a main clause, the finite verb normally comes in the second position. If something other than the subject comes first, the verb still stays second, and the subject moves after it.

Here, the sentence begins with the subordinate clause:

• Ef snuðið dettur á gólfið = If the pacifier falls on the floor

After that, the main clause begins. Since the first position in the overall sentence is already taken by the if-clause, the finite verb of the main clause comes next:

• þvæ ég það strax

So this is normal Icelandic word order.

Compare:

• Ég þvæ það strax. = I wash it right away.
• Ef snuðið dettur á gólfið, þvæ ég það strax. = If the pacifier falls on the floor, I wash it right away.

Þvæ is the 1st person singular present tense of þvo, meaning to wash.

So:

• að þvo = to wash
• ég þvæ = I wash

This is one of those verbs whose present-tense forms are not completely predictable from the infinitive, so it is worth memorizing.

In the sentence:

• þvæ ég það strax = I wash it right away

Það means it here, and it refers back to snuðið.

The noun snuð is neuter singular, so the pronoun that refers to it is also neuter singular:

• snuðið = the pacifier
• það = it

So:

• þvæ ég það = I wash it

This agreement in gender and number is very important in Icelandic.

Strax means right away, immediately, or at once.

In this sentence:

• þvæ ég það strax = I wash it right away

It is an adverb, and Icelandic adverbs are often fairly flexible in position, but the placement here is very natural. It comes after the object það.

Here ef means if.

It introduces a condition:

• Ef snuðið dettur á gólfið = If the pacifier falls on the floor

In English, if can also sometimes mean whether, but in this sentence it is clearly conditional, not a question of uncertainty.

Icelandic usually uses the indicative after ef when talking about a real or ordinary condition.

That is what is happening here:

• Ef snuðið dettur á gólfið = If the pacifier falls on the floor

This sounds like a normal, realistic possibility.

The subjunctive would be used in other kinds of meanings, but this sentence is just a straightforward condition, so the indicative is the natural choice.

The comma separates the subordinate if-clause from the main clause:

• Ef snuðið dettur á gólfið, þvæ ég það strax.

This is standard punctuation in Icelandic when a subordinate clause comes first.

So the structure is:

• subordinate clause: Ef snuðið dettur á gólfið
• main clause: þvæ ég það strax

These letters often stand out to English speakers.

• þ is like the th in thing

  • so þvæ begins with that sound

• ð is like the th in this, though in Icelandic it can be softer depending on position

  • in snuðið, it is part of the ending

• æ is pronounced roughly like i in fine or eye, though exact pronunciation depends on accent and context

  • so þvæ sounds approximately like thvai

A rough learner-friendly pronunciation of the whole sentence might be:

• Ef snuðið dettur á gólfið, þvæ ég það strax
• roughly: ev snu-thith det-tur au GOHL-vith, thvai yehg tha strax

That is only approximate, but it helps with the main sounds.

Yes.

In the first clause:

• Ef snuðið dettur á gólfið
• snuðið is the subject
• dettur is the verb

In the second clause:

• þvæ ég það strax
• ég is the subject
• þvæ is the verb
• það is the object

So the sentence switches from talking about what the pacifier does to what I do in response.