Θέλω ένα λάπτοπ που να χωράει εύκολα στην τσάντα και να μην είναι πολύ βαρύ.

Yes. In Modern Greek, many loanwords like λάπτοπ are treated as neuter and often stay indeclinable.

So you get:

• το λάπτοπ
• ένα λάπτοπ
• το βαρύ λάπτοπ

That is also why the adjective later is βαρύ and not βαρύς or βαριά.

Also, θέλω takes a direct object, and here that object is ένα λάπτοπ. In the neuter singular, the form ένα is the same for nominative and accusative.

Here που is the relative word meaning that / which.

It introduces a clause describing λάπτοπ:

• ένα λάπτοπ = a laptop
• που να χωράει εύκολα στην τσάντα = that fits easily in the bag
• και να μην είναι πολύ βαρύ = and is not very heavy / and isn’t too heavy

So που connects the noun λάπτοπ with the description that follows.

This is a very common pattern in Greek.

After words like θέλω, ψάχνω, χρειάζομαι, Greek often uses:

noun + που να + verb

to describe a desired characteristic, not just a factual one.

So:

• Θέλω ένα λάπτοπ που να χωράει... = I want a laptop that will / that can / that would fit...

This suggests a requirement or desired property.

If you said που χωράει, it would sound more like you are simply describing a laptop that in fact fits. That can also be possible in some contexts, but που να χωράει is especially natural when talking about what you want or are looking for.

Χωράει comes from χωράω / χωρώ, meaning to fit.

In this sentence, it appears after να, so it is in a subjunctive environment:

• να χωράει

The actual verb form looks the same as the present indicative form:

• χωράει = it fits
• να χωράει = to fit / that it fit

So the important thing is not a special ending here, but the fact that it follows να.

This is about aspect.

• να χωράει = imperfective aspect
• να χωρέσει = perfective aspect

In this sentence, the speaker wants a laptop with a general ongoing property: one that fits easily in the bag as a regular characteristic.

That is why να χωράει is natural here.

By contrast, να χωρέσει would point more to a single fitting event, like to fit on one occasion.

So:

• που να χωράει στην τσάντα = that fits in the bag, as a general trait
• να χωρέσει στην τσάντα = to fit in the bag on a particular attempt

Because εύκολα is an adverb, and it modifies the verb χωράει.

It means easily:

• χωράει εύκολα = fits easily

The forms εύκολος / εύκολη / εύκολο are adjectives and would describe a noun, not the action of fitting.

So Greek uses:

• adjective: ένα εύκολο μάθημα = an easy lesson
• adverb: μαθαίνω εύκολα = I learn easily

Same idea here:

• χωράει εύκολα = it fits easily

Στην is the contracted form of:

σε + την = στην

So:

• σε = in, into, at, to
• την = the (feminine singular)

Together:

• στην τσάντα = in the bag / into the bag

This contraction is extremely common in Modern Greek:

• στο = σε + το
• στον = σε + τον
• στη or στην = σε + τη(ν)

Because Greek uses μη(ν), not δεν, to negate verbs after να.

A useful rule is:

• δεν negates the indicative
• μη(ν) negates the subjunctive, imperative, and some other non-indicative forms

So:

• είναι = it is
• δεν είναι = it is not
• να είναι = to be / that it be
• να μην είναι = not to be / that it not be

So να δεν είναι is not correct Greek.

Because there are two coordinated verb phrases, and both belong to the same subjunctive pattern:

• που να χωράει εύκολα στην τσάντα
• και να μην είναι πολύ βαρύ

Greek normally repeats να before each coordinated verb when both are part of this structure. It keeps the sentence clear and natural.

So the idea is:

I want a laptop

• that fits easily in the bag
• and that is not very heavy

Greek marks both parts with να.

Because the adjective agrees with λάπτοπ, which is neuter singular.

The adjective βαρύς has these forms:

• masculine: βαρύς
• feminine: βαριά
• neuter: βαρύ

Since λάπτοπ is neuter, Greek uses:

• το λάπτοπ είναι βαρύ

Even though βαρύ comes after είναι, it still agrees with the noun it describes.

Yes, literally πολύ βαρύ means very heavy.

So:

• να μην είναι πολύ βαρύ literally = for it not to be very heavy

But in natural English, this often corresponds to not too heavy, because the speaker is expressing a practical preference.

So the Greek wording is slightly different from the most natural English wording, even if the overall meaning is the same.

If Greek wanted to make too heavy more explicit, it could use expressions like:

• υπερβολικά βαρύ = excessively heavy
• πάρα πολύ βαρύ = far too / extremely heavy, depending on context

But να μην είναι πολύ βαρύ is a very normal and natural way to express the idea here.