Losaðu reipið.

Losaðu is the singular imperative form of losa, so it means loosen! / release! / undo! when speaking to one person.

A useful way to think of it is:

• losa = the basic verb, to loosen / release / detach
• losaðu = loosen! / release! addressed to one person

In Icelandic, commands often use a special ending like -ðu in the singular imperative.

The -ðu marks a command to one person with many verbs.

So:

• losa = to loosen / release
• losaðu! = loosen! / release!

This is very common in Icelandic imperatives:

• opna → opnaðu! = open!
• borða → borðaðu! = eat!
• hlusta → hlustaðu! = listen!

So Losaðu reipið is a normal verb-first command.

It is addressed to one person.

The form losaðu is singular imperative. If you were speaking to more than one person, you would normally say:

• Losið reipið. = Loosen/Release the rope. said to several people

So the ending helps tell you who the command is aimed at.

Because reipið means the rope, while reipi means a rope or just rope.

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

So:

• reipi = rope / a rope
• reipið = the rope

That -ið is the definite article here.

It is the direct object of the verb losa, so it is in the accusative case.

However, with this noun, the nominative and accusative singular forms look the same, so you still see reipið.

In other words:

• the verb losa takes an object
• reipið is that object
• therefore it is accusative in function, even though the form looks the same as nominative

This is very common with neuter nouns in Icelandic.

It can cover several related meanings depending on context.

losa often means things like:

• loosen
• release
• free
• detach
• sometimes untie, if that is what loosening the rope involves

So Losaðu reipið could be understood as:

• Loosen the rope
• Release the rope
• Untie the rope

The best English translation depends on the situation. If the rope is tied in a knot, untie the rope may be the most natural translation. If it is under tension or fastened somehow, loosen or release may fit better.

A simple learner-friendly approximation is:

• reipið ≈ RAY-pith

A few pronunciation notes:

• ei is pronounced roughly like ay in say
• p is an ordinary p
• ð is like th in this or the, not like th in thing

So the whole sentence is roughly:

• LO-sa-thu RAY-pith

That said, Icelandic pronunciation is a bit subtler than English spelling can show, so this is only an approximation.

Because this is a command. In Icelandic, imperatives normally begin with the verb.

So:

• Losaðu reipið. = Loosen the rope.

That verb-first structure is the normal and expected order for a direct command.

Yes. Losaðu reipið. is a straightforward command. If you want to sound softer, Icelandic often uses a question instead, similar to English.

For example:

• Geturðu losað reipið? = Can you loosen the rope?
• Viltu losa reipið? = Would you loosen the rope? / Do you want to loosen the rope?

So the original sentence is correct, but it is more direct than these softer alternatives.

Yes: reipi is a neuter noun.

That matters because neuter nouns often have the same form in the singular nominative and accusative, which helps explain why you see reipið here.

A quick summary:

• reipi = neuter noun meaning rope
• reipið = the rope
• in this sentence it functions as the direct object of the verb

So even though the form is simple, it is doing several grammatical jobs at once.