Learn Hardcore Greek: Μου αρέσει η δημιουργία απλών διαλόγων, τους οποίους μπορώ να θυμάμαι εύκολα. - I like the creation of simple dialogues, which I can remember easily.

Μου αρέσει literally means It is pleasing to me.
- αρέσει = is pleasing (3rd person singular)
- μου = to me (indirect object in the genitive)

So the logical structure is:

Η δημιουργία απλών διαλόγων (the creation of simple dialogues) = subject
αρέσει = verb
μου = to me

If you said αρέσω, that would mean I am pleasing (to someone), e.g. Του αρέσω = He likes me (literally: I am pleasing to him), not I like.

What exactly is μου here – what case is it, and what does it mean?

μου is:

the genitive form of the first person singular pronoun (I → me / my),
a clitic (weak pronoun) attached to the verb,
and it marks an indirect object with the meaning to me.

So in Μου αρέσει η δημιουργία..., μου means to me, not my:

Μου αρέσει... = It is pleasing to me / I like...
If it were η δημιουργία μου, that would mean my creation, which is different.

Why is it η δημιουργία (a noun) instead of a verb like να δημιουργώ?

Greek often uses a noun as the subject of αρέσει:

Μου αρέσει η μουσική. – I like music.
Μου αρέσει η ησυχία. – I like quiet.

Here, η δημιουργία απλών διαλόγων is treated as a thing / activity:

Μου αρέσει η δημιουργία απλών διαλόγων
= The creation of simple dialogues is pleasing to me.

You can also use a verb:

Μου αρέσει να δημιουργώ απλούς διαλόγους.
= I like to create simple dialogues.

Both are correct. Using η δημιουργία sounds a bit more noun-like / abstract (the activity of creating), while να δημιουργώ focuses more on me doing the action.

Why is there a definite article η before δημιουργία?

In Greek, abstract nouns in this kind of general liking structure usually take the definite article:

Μου αρέσει η μουσική. – I like music.
Μου αρέσει ο χορός. – I like dancing (dance).
Μου αρέσει η δημιουργία απλών διαλόγων. – I like (the) creation of simple dialogues.

If you drop the article (Μου αρέσει δημιουργία απλών διαλόγων), it sounds unnatural or very marked. Greek is generally more article-heavy than English, especially with abstract or generic nouns.

Why is it δημιουργία απλών διαλόγων and not δημιουργία απλούς διαλόγους?

Because in Greek, when you say the creation of X, X normally goes in the genitive:

η δημιουργία ενός κειμένου – the creation of a text
η κατασκευή σπιτιών – the construction of houses
η μελέτη της γλώσσας – the study of the language

So:

η δημιουργία απλών διαλόγων
= the creation of simple dialogues
→ απλών διαλόγων is genitive plural.

If you said απλούς διαλόγους, that would be accusative plural, which would fit as a direct object, not as a genitive complement of η δημιουργία. Here, διαλόγων depends on δημιουργία, so it must be in the genitive.

Why is απλών in that form? How does it agree with διαλόγων?

απλών is the genitive plural of the adjective απλός (simple).

απλός declines and must agree with the noun in:

gender: διαλόγων is masculine → απλών masculine
number: διαλόγων is plural → απλών plural
case: διαλόγων is genitive → απλών genitive

So the pair is:

masculine, genitive, plural: απλών διαλόγων = of simple dialogues.

Other forms for comparison:

nominative singular masculine: απλός διάλογος
accusative plural masculine: απλούς διαλόγους
genitive plural masculine: απλών διαλόγων

Does η δημιουργία απλών διαλόγων mean the dialogues are simple, or that the creation is simple?

The structure η δημιουργία απλών διαλόγων means:

the creation of simple dialogues → the dialogues are simple.

If you wanted to say that the act of creating is simple, you’d say instead:

η απλή δημιουργία διαλόγων – the simple creation of dialogues.

So:

η δημιουργία απλών διαλόγων → simplicity is a property of the dialogues.
η απλή δημιουργία διαλόγων → simplicity is a property of the creation process.

What is τους οποίους exactly, and why that form?

τους οποίους is the relative pronoun ο οποίος in the:

masculine
accusative
plural

It agrees in gender and number with what it refers to (the dialogues), but its case (accusative) is determined by its function inside the relative clause.

Inside the clause τους οποίους μπορώ να θυμάμαι εύκολα:

τους οποίους is the direct object of θυμάμαι → therefore accusative.

So:

Antecedent idea: (τους) διαλόγους = masculine plural (even though in the main phrase they appear as απλών διαλόγων in the genitive).
Relative pronoun: τους οποίους = whom / which (ones) I can remember.

Why do we need both τους and οποίους? Could we just say οποίους?

In modern Greek, the relative pronoun ο οποίος is always used together with its article:

Correct: ο οποίος, η οποία, το οποίο, οι οποίοι, τις οποίες, τους οποίους, etc.
οποίους alone is not used as a standard relative pronoun.

So τους οποίους is one unit: the ones whom / which.

You cannot normally drop τους here. The article is part of the relative system (unlike English, where who/which stand alone).

Can I replace τους οποίους with που? If so, is there a difference?

Yes, you can:

Μου αρέσει η δημιουργία απλών διαλόγων, που μπορώ να θυμάμαι εύκολα.

This is fully grammatical and very common.

Differences:

που is more neutral / everyday.
ο οποίος / τους οποίους is often a bit more formal/written or explicit, and sometimes clearer in complicated sentences.

In this simple sentence, both are fine; που is what you would probably hear most in everyday speech.

Why is there a comma before τους οποίους?

The comma separates the main clause from the relative clause:

Main part: Μου αρέσει η δημιουργία απλών διαλόγων
Relative clause: τους οποίους μπορώ να θυμάμαι εύκολα

In Greek, a comma before που or ο οποίος is normally used when the relative clause is non‑defining (adding extra information about something already identified), similar to English:

I like the creation of simple dialogues, which I can remember easily.

Here, the comma is natural and recommended, though in some brief sentences in informal writing people may omit it.

Why is it μπορώ να θυμάμαι and not μπορώ να θυμηθώ?

The difference is aspect:

θυμάμαι = imperfective aspect → focuses on the ongoing / repeated ability or state:
- μπορώ να θυμάμαι = I can (generally) remember / I am able to keep them in mind.
θυμηθώ = aorist aspect (subjunctive) → focuses on a single event of remembering:
- μπορώ να θυμηθώ = I can manage to remember (them at a given moment).

In your sentence, you mean you like that these dialogues are easy to remember in general, so μπορώ να θυμάμαι εύκολα (habitual/ongoing ability) is the natural choice.

What kind of verb is θυμάμαι? Why does it look like a passive form?

Θυμάμαι is one of those Greek verbs that:

has a middle / passive form in ‑μαι,
but has active meaning: I remember.

You use it with a direct object:

Θυμάμαι τους διαλόγους. – I remember the dialogues.
Μπορώ να θυμάμαι τους διαλόγους. – I can remember the dialogues.

There is an active form θυμώ in older or more literary language, but in modern everyday Greek, θυμάμαι is standard for I remember.

Why is it εύκολα and not εύκολο or εύκολη?

Εύκολα is used here as an adverb: it modifies the verb θυμάμαι (how I remember → easily).

Greek often uses the neuter plural / neuter form of adjectives adverbially:

τρέχω γρήγορα – I run fast.
μιλάω καθαρά – I speak clearly.
θυμάμαι εύκολα – I remember easily.

Forms like εύκολο, εύκολη are adjectives, used with nouns:

εύκολος διάλογος – an easy dialogue (masc.)
εύκολη άσκηση – an easy exercise (fem.)
εύκολο κείμενο – an easy text (neut.)

Here we’re not describing a noun but the manner of remembering, so the adverbial εύκολα is correct.

Can εύκολα move in the sentence, and does that change the meaning?

Yes, Greek adverbs like εύκολα are relatively flexible. You could say:

τους οποίους μπορώ να θυμάμαι εύκολα (original)
τους οποίους μπορώ εύκολα να θυμάμαι
τους οποίους εύκολα μπορώ να θυμάμαι

The basic meaning (I can easily remember them) stays the same.
Minor differences:

Placing εύκολα closer to μπορώ can slightly highlight the ease of the ability.
Placing it closer to θυμάμαι can slightly highlight the ease of the act of remembering.

In normal speech, all of these would be understood the same way; the original order is very natural.