Andaðu rólega.

Andaðu is the singular imperative of the verb að anda (to breathe).

So the sentence is a command or instruction directed at one person:

• að anda = to breathe
• andaðu = breathe!

This kind of form is very common in Icelandic instructions, coaching, and everyday speech.

The ending -ðu is a common way to form the 2nd person singular imperative in Icelandic.

So:

• að anda = infinitive, to breathe
• andaðu = imperative, breathe!

You will see the same pattern in other verbs too:

• að tala → talaðu! = speak!
• að hlusta → hlustaðu! = listen!

For learners, it is often easiest to think of -ðu as a very typical singular command ending.

Because Icelandic, like English, usually leaves out the subject pronoun in commands.

Compare English:

• Breathe calmly. not usually
• You breathe calmly.

Icelandic works the same way here:

• Andaðu rólega.

The you is understood automatically.

Rólega is an adverb. It describes how the action is done.

It comes from the adjective rólegur:

• rólegur = calm, quiet
• rólega = calmly, quietly, gently

So in this sentence, rólega tells you the manner of breathing.

It is formed from the adjective rólegur by using the adverbial ending -lega.

A very common Icelandic pattern is:

• adjective → adverb

Here:

• rólegur = calm
• rólega = calmly

This is somewhat similar to English calm → calmly, although Icelandic does not always match English word-for-word.

Its core meaning is calmly, gently, or in a relaxed way.

In the context of breathing, that can naturally suggest slow, relaxed breathing, so English translations may vary:

• Breathe calmly
• Breathe gently
• Breathe slowly and calmly

If you specifically wanted to emphasize slowly, Icelandic often uses hægt:

• Andaðu hægt. = Breathe slowly.

So rólega is more about the calm quality of the action than pure speed.

The most natural word order for a simple command is:

verb + adverb

So:

• Andaðu rólega.

Putting rólega first is possible in some contexts, but it sounds more marked or emphatic:

• Rólega andaðu would feel unusual in normal everyday speech.

For a basic instruction, Andaðu rólega is the standard order.

To more than one person, you use the plural imperative:

• Andið rólega. = Breathe calmly. / Breathe calmly, everyone.

So:

• Andaðu rólega. = said to one person
• Andið rólega. = said to more than one person

It is simply the normal singular command form.

Icelandic does not have the same kind of everyday formal you distinction that many European languages do. So Andaðu rólega is just the ordinary way to say this to one person.

If you are speaking to a group, use:

• Andið rólega

But there is no special separate formal singular version that learners need to memorize here.

A rough English-friendly pronunciation is:

AN-da-thu RO-le-ga

A few helpful notes:

• ð is like the th in this, though in real speech it can sound quite soft.
• ó is a long vowel, roughly like o in go, but not exactly the same as English.
• Stress in Icelandic usually falls on the first syllable:
  • ANdaðu
  • RÓlega

You do not need perfect pronunciation right away, but keeping the stress on the first syllable is important.

The infinitive is:

• að anda = to breathe

If you say just anda rólega, that is the infinitive plus an adverb, so it means something more like to breathe calmly, not a direct command.

To give an instruction, Icelandic normally uses the imperative:

• Andaðu rólega.

So if you want to tell someone to do it, andaðu is the right form.