Ég rugla stundum hægri og vinstri saman.

Saman literally means together, but with rugla it forms a very common expression: rugla X og Y saman.

That whole pattern means to mix up X and Y or to confuse X and Y with each other. So saman is an important part of the expression, not just an optional extra word.

That is normal Icelandic word order for this kind of verb + particle expression.

In a dictionary or infinitive, you may see að rugla saman. But in a full sentence, the particle often comes later, especially after the object:

Ég rugla hægri og vinstri saman.

That sounds very natural. Icelandic often places short particle-like words this way.

Stundum means sometimes.

Its position is flexible. In your sentence, it comes after the verb:

Ég rugla stundum hægri og vinstri saman.

But you could also say:

Stundum rugla ég hægri og vinstri saman.

That version puts more focus on sometimes. Notice that when stundum comes first, the verb still has to stay in second position: Stundum rugla ég..., not Stundum ég rugla....

They are originally adjective-type words meaning right and left, but here they are being used on their own, almost like nouns.

So in this sentence they mean:

• hægri = the right / right side
• vinstri = the left / left side

English does the same kind of thing when we say right and left without adding a noun like side.

No. In this sentence, hægri and vinstri stand perfectly well on their own.

So you do not need to say something like hægri hlið or vinstri hönd unless you specifically want to talk about a particular right hand, left hand, right side, and so on.

Here the general ideas right and left are enough.

Because Icelandic often uses these words without an article when speaking about the concepts in general.

So hægri og vinstri naturally means right and left as general categories. English also often drops extra words here: we normally say I mix up right and left, not I mix up the right and the left.

Yes. That is another very natural way to express the same idea.

There is a useful difference:

• Ég rugla hægri og vinstri saman = I mix up right and left
• Ég ruglast á hægri og vinstri = I get confused about right and left

So rugla is more like actively mixing two things up, while ruglast describes becoming confused.

Normally, no. Icelandic usually keeps the subject pronoun.

So Ég rugla... is the normal way to say I mix up.... Unlike in some languages, you generally do not just drop I and let the verb ending do all the work.

Yes. Og simply means and.

The structure is basically:

• rugla
• hægri og vinstri
• saman

So literally the idea is something like mix right and left together, which naturally becomes mix up right and left in English.

Yes, to some extent. Icelandic word order is flexible, but not random.

For example, these are natural:

• Ég rugla stundum hægri og vinstri saman.
• Stundum rugla ég hægri og vinstri saman.

The second version emphasizes sometimes a bit more.

The important rule is that in a main clause, the finite verb usually stays in second position. That is why Stundum rugla ég... is correct, while Stundum ég rugla... is not.