Η γιατρός είπε να μην σκύβω πολύ, γιατί ο σβέρκος μου θέλει ξεκούραση.

Because γιατρός is very often used as a common-gender profession noun in Modern Greek.

• ο γιατρός = the male doctor
• η γιατρός = the female doctor

So the article shows the gender here, not the noun ending. You may also hear other feminine forms in some contexts, but η γιατρός is the standard neutral way to say female doctor.

Greek normally does not use an infinitive the way English does. So instead of something like said not to bend, Greek uses:

• είπε να... = said to..., told someone to..., said that one should...

In this sentence, είπε να μην σκύβω πολύ means something like:

• she said I shouldn’t bend too much
• or she told me not to bend too much

So να + verb is doing the job that an English infinitive or reported instruction might do.

Because δεν and μη(ν) are used in different kinds of clauses.

• δεν negates normal statements
• μη(ν) negates να-clauses, commands, wishes, and similar non-indicative forms

Here we have να μην σκύβω, so μην is the correct negative.

Compare:

• Δεν σκύβω πολύ = I do not bend much
• Να μην σκύβω πολύ = that I should not bend much / not to bend much

Formally, yes, it is built from the present stem, but after να it is better to think in terms of aspect, not simple tense.

Here σκύβω shows the imperfective aspect, which suggests:

• repeated action
• ongoing action
• general behavior

So να μην σκύβω πολύ means not to keep bending too much or not to bend too much in general, not necessarily only right now.

Because σκύβω and σκύψω differ in aspect.

• σκύβω = imperfective, ongoing/repeated/general
• σκύψω = perfective, single complete act

A doctor’s advice is usually about a general habit or repeated action, so να μην σκύβω πολύ sounds natural.

If you said να μην σκύψω πολύ, it would sound more like:

• not to bend down once
• not to bend too far at a particular moment

So the sentence uses the form that best matches general medical advice.

Σκύβω means bend, stoop, or lean downward.

Depending on context, it can mean:

• bend forward
• stoop down
• lower the upper body

In this sentence, it means something like bend over or stoop forward, which fits the reference to the neck.

Σβέρκος usually means the back of the neck or the nape.

It is more specific than λαιμός, which often means:

• the neck in general
• or even the throat area, depending on context

So ο σβέρκος μου is not just my neck in the broadest sense, but more specifically the back of my neck.

Because Greek weak possessive pronouns usually come after the noun.

So Greek says:

• ο σβέρκος μου = my neck
• το χέρι μου = my hand
• η μέση μου = my waist/back

This is the normal pattern. English puts my before the noun, but Greek often puts the possessive pronoun after it.

Literally, yes: θέλει means wants. But in everyday Greek, θέλω is often used in a broader, very natural way to mean:

• needs
• could use
• requires

So ο σβέρκος μου θέλει ξεκούραση means:

• my neck needs rest
• my neck could use some rest

A more formal or more literal needs version would be χρειάζεται ξεκούραση.

Because ξεκούραση here is an abstract noun meaning rest in a general sense.

Greek often leaves out the article in expressions like this, especially when talking about something uncountable or general:

• θέλει ξεκούραση = needs rest
• θέλει ύπνο = needs sleep

If you added μια, it would sound more like a bit of rest or some rest, which is possible, but the version without an article is very natural here.

Good question. Greek could absolutely say:

• Η γιατρός μού είπε να μην σκύβω πολύ

That would explicitly mean The doctor told me not to bend too much.

In your sentence, the indirect object is simply not stated. Greek often leaves it out when it is obvious from context. Since the rest of the sentence is clearly about the speaker’s condition, the listener understands that this is advice given to me.

So:

• Η γιατρός είπε... = The doctor said...
• Η γιατρός μού είπε... = The doctor told me...

Both are possible, with a slight difference in explicitness.

Because γιατί introduces a reason clause:

• γιατί ο σβέρκος μου θέλει ξεκούραση = because my neck needs rest

In Greek, it is very common to separate that explanatory clause with a comma, just as English often separates a reason clause in longer sentences.

Yes. Γιατί can mean both:

• because
• why

Context tells you which meaning is intended.

Here it clearly means because, since it introduces the explanation:

• ...γιατί ο σβέρκος μου θέλει ξεκούραση = ...because my neck needs rest

If it were a question, then γιατί could mean why.

It is somewhere between the two, depending on how you translate it.

• είπε by itself is literally said
• but είπε να μην... often functions like told someone not to... or said that one shouldn’t...

So a natural English translation might be:

• The doctor said not to bend too much
• The doctor told me not to bend too much
• The doctor said I shouldn’t bend too much

All of those capture the Greek fairly well.