Ekki líkja eftir mér.

• Ekki = not / don’t
• líkja = to imitate / to copy in this expression
• eftir = after
• mér = me in the dative case

So although the literal pieces look a bit like not imitate after me, the natural meaning is Don’t imitate me.

In Icelandic, negative commands are very often made with:

ekki + infinitive

So:

• Ekki fara! = Don’t go!
• Ekki snerta! = Don’t touch!
• Ekki líkja eftir mér! = Don’t imitate me!

This is a very common pattern, and it is one of the first imperative patterns learners meet.

Because in a negative command, Icelandic commonly uses the infinitive after ekki.

So instead of using a special imperative verb form here, Icelandic says:

• Ekki líkja ...
• literally: not to-imitate ...
• naturally: don’t imitate ...

This is normal and idiomatic.

It is understood rather than stated.

Commands in Icelandic, like in English, often leave out the subject:

• Ekki líkja eftir mér. = Don’t imitate me.

If you want to add the subject for emphasis, you can, for example:

• Þú, ekki líkja eftir mér. = You, don’t imitate me.
• Þið, ekki líkja eftir mér. = You all, don’t imitate me.

But most of the time, the subject is simply omitted.

Because eftir takes the dative in this expression.

The pronoun ég has different case forms:

• ég = I
• mig = me (accusative)
• mér = me (dative)
• mín = my (genitive)

Since the phrase is líkja eftir e-m, where e-m is dative, you get:

• eftir mér = after me / me in the idiomatic sense

So mér is required here.

Yes. In this sentence, líkja eftir is best learned as a set expression meaning:

• to imitate
• to copy someone’s behavior

So it is better not to think of líkja and eftir completely separately here. Together, they form the meaning.

This is useful because líkja can mean different things in other constructions. For example, líkja A við B means to compare A to B, which is a different pattern.

The positive command to one person would normally be:

• Líktu eftir mér! = Imitate me!

The negative command is commonly:

• Ekki líkja eftir mér! = Don’t imitate me!

So positive and negative commands do not necessarily use the same structure in Icelandic.

On its own, Ekki líkja eftir mér can be used generally and does not explicitly mark singular vs. plural.

Context usually tells you whether the speaker is talking to:

• one person
• several people

If you want to make it explicit, you can add the pronoun:

• Þú, ekki líkja eftir mér. = You, don’t imitate me.
• Þið, ekki líkja eftir mér. = You all, don’t imitate me.

So the basic negative-command form itself is flexible.

A helpful approximation for English speakers is:

• líkja ≈ LEE-kya

A few pronunciation notes:

• í is a long ee sound
• kj is not pronounced like plain English k+j; it comes out more like a ky-type sound
• mér sounds roughly like myair or myehr, depending on accent

You do not need a perfect accent right away, but it helps to hear native recordings because Icelandic consonant combinations can be tricky from spelling alone.

Yes. A very common alternative is:

• Ekki herma eftir mér.

The verb herma eftir also means to imitate / mimic and is extremely common in everyday speech.

So both of these are possible:

• Ekki líkja eftir mér.
• Ekki herma eftir mér.

Depending on context, many speakers may find herma eftir the more everyday, direct verb for imitation.

No, not normally.

Líkja eftir mér means imitate me.

If you want to say Don’t compare yourself to me, you would use a different construction, such as:

• Ekki líkja þér við mig.

That is a good example of why it helps to learn the whole pattern:

• líkja eftir e-m = imitate someone
• líkja e-u/þér við e-ð/e-n = compare something/yourself to something/someone