Learn Hardcore Greek: Δεν μου αρέσει όταν το φαγητό είναι πολύ αλμυρό ή όταν το τσάι είναι πικρό. - I don’t like it when the food is very salty or when the tea is bitter.

English: I like the food.
Subject = I, object = the food.
Greek: Μου αρέσει το φαγητό.
Literal structure = The food pleases me.
Subject = το φαγητό, indirect object = μου (to me).

So μου αρέσει literally means it pleases me or it is pleasing to me.
You almost never say εγώ αρέσω το φαγητό; that would be ungrammatical.

What exactly is μου here, and why that form?

Μου is the weak (clitic) genitive form of εγώ (I), and in this structure it means to me.

εγώ = I (strong form, nominative)
μου = to me / my (weak form, genitive)

With αρέσει, you always use the genitive pronoun:

Μου αρέσει = It pleases me.
Σου αρέσει = It pleases you (singular).
Του / Της / Του αρέσει = It pleases him / her / it.

It must come before the verb:
Δεν μου αρέσει..., not ~μου δεν αρέσει~.

Why do we use δεν and not όχι to say not?

Δεν is the normal verb negation word; it goes directly before the verb:

Μου αρέσει. = I like it.
Δεν μου αρέσει. = I do not like it.

Όχι means no as a standalone word or negating a whole statement:

Όχι, δεν μου αρέσει. = No, I do not like it.
Όχι πολύ. = Not really / not much.

So in sentences like this, you use δεν with the verb, not όχι.

Why is there no separate it in Greek, like in I don’t like it when…?

Greek usually does not use a dummy it the way English does.

In Δεν μου αρέσει όταν το φαγητό είναι πολύ αλμυρό...:

The whole clause όταν το φαγητό είναι πολύ αλμυρό functions as the thing that pleases/doesn’t please you.
There is no extra pronoun like English it; the verb αρέσει just takes that clause.

So Greek says literally: Does not please me when the food is very salty…

When should I use όταν instead of αν for when / if?

In this sentence, όταν expresses a general, repeated situation:

Δεν μου αρέσει όταν το φαγητό είναι πολύ αλμυρό.
= I don’t like it when (whenever) the food is very salty.

Όταν is used for when in:

General, repeated situations (when I eat, when it rains).
Specific time references in the past or future (when I arrived, when you come).

Αν means if (a condition), not when:

Δεν μου αρέσει αν το φαγητό είναι πολύ αλμυρό.
= I don’t like it if the food is very salty. (more hypothetical)

Here, όταν is more natural because it refers to your general taste, not a one‑time condition.

Do I really need to repeat όταν before το τσάι?

Repeating όταν is very natural and clear:

...όταν το φαγητό είναι πολύ αλμυρό ή όταν το τσάι είναι πικρό.

You could also say:

Δεν μου αρέσει όταν το φαγητό είναι πολύ αλμυρό ή το τσάι είναι πικρό.

This is still correct and understandable.
Repeating όταν slightly emphasizes that these are two separate situations:

When the food is too salty.
When the tea is bitter.

In everyday speech, both versions are used. The bookish, very clear version often repeats όταν.

Why is είναι repeated? Can I drop the second είναι?

The given sentence:

...όταν το φαγητό είναι πολύ αλμυρό ή όταν το τσάι είναι πικρό.

You can quite naturally drop the second είναι and say:

...όταν το φαγητό είναι πολύ αλμυρό ή όταν το τσάι πικρό.

This sounds a bit more compact and is common in speech.
Keeping both είναι is perfectly correct and perhaps a little clearer for learners.

Why do we use το before φαγητό and τσάι when English just says food and tea?

Modern Greek uses the definite article το much more than English:

Μου αρέσει το φαγητό.
= I like food (in general) / I like the food, depending on context.
Μου αρέσει το τσάι.
= I like tea (in general) / I like the tea.

In generic statements about types of things, Greek often still uses the definite article:

Μου αρέσει το κρέας. = I like meat.
Μου αρέσει ο καφές. = I like coffee.

So here το φαγητό and το τσάι are generic: the food / food and the tea / tea. The context tells you it is about your general preference.

Why are αλμυρό and πικρό in the -ό form and not αλμυρός / πικρός?

Adjectives in Greek agree with the noun in gender, number, and case.

το φαγητό is neuter singular.
→ adjective must be neuter singular: αλμυρό.
το τσάι is also neuter singular.
→ adjective must be neuter singular: πικρό.

So:

πολύ αλμυρό φαγητό = very salty food.
πικρό τσάι = bitter tea.

Αλμυρός / πικρός are the masculine singular forms (for ο‑nouns), e.g.:

αλμυρός μεζές (masculine).
πικρός καφές (masculine).

What is the role of πολύ here? Does it mean very or too?

In πολύ αλμυρό, πολύ is an adverb modifying the adjective αλμυρό:

πολύ αλμυρό = very salty.
πολύ πικρό = very bitter.

In many everyday contexts, πολύ can also carry the idea of too (excessive), especially when the sentence is negative or critical, like this one. So it can feel close to:

I don’t like it when the food is too salty.

If you want to make too very clear, you can say:

πάρα πολύ αλμυρό = too salty (stronger).
πάρα πολύ πικρό = too bitter.

Why is the verb αρέσει singular here, not αρέσουν, when there are two things (food and tea)?

In this sentence, the grammatical subject of αρέσει is not a plural list of nouns. It is the whole όταν‑clause (or clauses) functioning as something like the situation when….

Δεν μου αρέσει όταν το φαγητό είναι πολύ αλμυρό ή όταν το τσάι είναι πικρό.

Think of it as:

I don’t like it when (this or that happens).

The subject is effectively το όταν‑συμβαίνει‑αυτό, which is singular in Greek, so αρέσει stays singular.

If you make the food and the tea themselves the direct subject of liking, then you use plural:

Δεν μου αρέσουν τα πολύ αλμυρά φαγητά και τα πικρά τσάγια.
= I don’t like very salty foods and bitter teas.

Could I say this using nouns instead of όταν‑clauses, like I don’t like very salty food or bitter tea?

Yes. A natural version is:

Δεν μου αρέσει το πολύ αλμυρό φαγητό ή το πικρό τσάι.

Here:

το πολύ αλμυρό φαγητό = very salty food.
το πικρό τσάι = bitter tea.

This focuses on types of food and tea.
The original version with όταν focuses more on situations (when they are like that). Both are correct; it is just a difference in style.

Can I change the word order, like Δεν μου αρέσει όταν είναι πολύ αλμυρό το φαγητό?

Yes, Greek word order is quite flexible. You could say:

Δεν μου αρέσει όταν είναι πολύ αλμυρό το φαγητό ή όταν είναι πικρό το τσάι.

This gives a bit of emphasis to the adjectives (πολύ αλμυρό, πικρό). All of these are fine:

όταν το φαγητό είναι πολύ αλμυρό
όταν είναι πολύ αλμυρό το φαγητό

As a learner, it is simpler to keep the basic order:

όταν + [subject] + [verb] + [rest].

Can I use εμένα instead of μου for emphasis, like Εμένα δεν μου αρέσει…?

Yes. To emphasize I (as opposed to other people), you can add the strong pronoun:

Εμένα δεν μου αρέσει όταν το φαγητό είναι πολύ αλμυρό...
= As for me / Personally, I don’t like it when…

Structure:

Εμένα = strong emphatic form (me).
μου = weak pronoun required by αρέσει (to me).

You almost always keep μου with αρέσει; εμένα is optional and used only for emphasis.

In speech I often hear something like Δε μ’ αρέσει. Is that the same as Δεν μου αρέσει?

Yes, it is the same expression, just in a more colloquial contracted form:

Δεν μου αρέσει → Δε μου αρέσει → Δε μ’ αρέσει.

Notes:

The ν in δεν is often dropped before consonants: δεν → δε.
The vowel ου in μου contracts to μ’ before a vowel sound (αρέσει).

In careful writing you will usually see Δεν μου αρέσει, but in everyday speech Δε μ’ αρέσει is extremely common and natural.