Θέλω να καθίσω εκεί που έχει σκιά.

In Modern Greek, verbs like θέλω are usually followed by a να-clause rather than an infinitive.

So English I want to sit becomes:

θέλω να καθίσω

Greek does not normally use a separate infinitive the way English does. The combination να + verb is the standard way to say things like:

• I want to go → θέλω να πάω
• I want to eat → θέλω να φάω
• I want to sit → θέλω να καθίσω

So να is not optional here.

καθίσω and κάθομαι express slightly different ideas.

• καθίσω = sit down / perform the action of taking a seat
• κάθομαι = be sitting / sit as a state

In this sentence, the speaker wants to choose a place and then sit there, so καθίσω is the natural choice.

Compare:

• Θέλω να καθίσω εκεί. = I want to sit down there.
• Θέλω να κάθομαι εκεί. = I want to be sitting there / sit there regularly.

So καθίσω is used because it focuses on the single action.

Not by itself. The form καθίσω can appear in different constructions.

• θα καθίσω = I will sit
• να καθίσω = that I sit / to sit, in a να-clause

So the form looks the same, but the particle before it changes the meaning:

• θα gives future
• να gives a subjunctive-type meaning

Here, because it is να καθίσω, it is not simply future tense.

εκεί που means something like there where or more naturally where / in the place where.

In this sentence, it introduces the place the speaker wants to sit:

εκεί που έχει σκιά = where there is shade

A useful way to think of it is:

• εκεί = there
• που = where/that

Together, they point to a specific kind of place: that spot where...

Both can be used, but που is extremely common in everyday Greek.

You could also say:

Θέλω να καθίσω όπου έχει σκιά.

That sounds a bit more formal or neat in style.
The version with εκεί που is very natural in spoken Greek.

Very roughly:

• εκεί που = common, conversational, often slightly more concrete
• όπου = also correct, often a bit more formal or compact

Because έχει is a very natural way in Greek to express that a place has shade.

So:

• εκεί που έχει σκιά = where there is shade / where it is shady

This is idiomatic Greek. English often says there is shade, but Greek commonly says it has shade when talking about a place.

You might also hear:

• Έχει ήλιο εδώ. = It’s sunny here.
• Έχει σκιά εκεί. = There’s shade there.

Using υπάρχει σκιά is possible, but it sounds less natural in this everyday context.

Because σκιά here is being used in a general, non-specific sense: shade as a condition or feature of the place.

So:

• έχει σκιά = it has shade

If you used the article, τη σκιά, it would sound more like a specific shadow/shade already known from context.

Compare:

• Θέλω να κάτσω εκεί που έχει σκιά. = I want to sit where there is shade.
• Βλέπεις τη σκιά του δέντρου; = Do you see the tree’s shadow?

So the absence of the article is natural here.

It can mean both, depending on context.

• shadow = the shadow cast by something
• shade = protection from the sun

In this sentence, shade is the better meaning, because the speaker wants to sit somewhere comfortable, out of the sun.

So although the Greek word is the same, the context tells you which English word fits best.

Yes. κάτσω is very common in everyday speech.

So you will often hear:

Θέλω να κάτσω εκεί που έχει σκιά.

This means the same thing and sounds very natural.
The pair is roughly:

• καθίζω / καθίσω = a bit more standard or careful
• κάθομαι / κάτσω = very common in spoken Greek

Both are useful to know.

Yes, Greek word order is flexible.

The original sentence is the most neutral:

Θέλω να καθίσω εκεί που έχει σκιά.

But you could also say:

Εκεί που έχει σκιά θέλω να καθίσω.

This puts more emphasis on the shady place.

So the order can change for emphasis, but the original version is the safest one to use as a learner.

In standard Greek, που έχει σκιά by itself does not work well here.

You would normally say one of these:

• Θέλω να καθίσω εκεί που έχει σκιά.
• Θέλω να καθίσω όπου έχει σκιά.
• Θέλω να καθίσω στο μέρος που έχει σκιά.

So yes, if you use που in this structure, you generally need something like εκεί or στο μέρος before it.

It functions like a place expression: the place where there is shade.

You can think of it as short for:

εκείνο το μέρος που έχει σκιά = that place which has shade

But Greek often leaves out μέρος because it is understood.

So the sentence structure is basically:

• Θέλω = I want
• να καθίσω = to sit down
• εκεί που έχει σκιά = where there is shade

That last part tells you where the speaker wants to sit.