Με το κατσαβίδι έσφιξα τη βίδα στο ράφι, γιατί είχε χαλαρώσει.

This is a very natural Greek word order when the speaker wants to foreground the means/instrument used.

• Με το κατσαβίδι = with the screwdriver
• Then comes the verb: έσφιξα = I tightened

So the sentence literally begins with something like:

• With the screwdriver, I tightened...

This does not mean the word order is fixed. You could also say:

• Έσφιξα τη βίδα στο ράφι με το κατσαβίδι.

That version sounds a bit more neutral. Putting Με το κατσαβίδι first gives it more emphasis.

Here με means with, in the sense of using something as a tool:

• Με το κατσαβίδι = with the screwdriver / using the screwdriver

Yes, με very often means with, but its exact meaning depends on context. Common uses include:

• with someone: με τον φίλο μου = with my friend
• by means of / using: με το κατσαβίδι = with the screwdriver
• sometimes in expressions of manner: με χαρά = with खुशी / gladly

In this sentence, it is clearly the instrumental use.

Good question. In Modern Greek, με takes the accusative case.

So:

• nominative: το κατσαβίδι
• accusative: το κατσαβίδι

Because κατσαβίδι is a neuter noun, the nominative and accusative look the same in the singular.

Compare with a masculine noun, where the difference is easier to see:

• nominative: ο φίλος
• accusative: τον φίλο
• με τον φίλο = with the friend

So in your sentence, το κατσαβίδι is accusative, even though its form does not change.

Because the verb already shows the subject.

• έσφιξα = I tightened

The ending -α tells you the subject is I (first person singular), so Greek usually leaves the pronoun out unless it is needed for emphasis or contrast.

For example:

• Έσφιξα τη βίδα. = I tightened the screw.
• Εγώ έσφιξα τη βίδα. = I tightened the screw.
  (with extra emphasis on I)

Greek does this all the time, so omitted subject pronouns are very normal.

Because έσφιξα is the aorist (simple past), while σφίγγω is the present.

• σφίγγω = I tighten / I am tightening
• έσφιξα = I tightened

The sentence describes a completed action in the past: the speaker tightened the screw. That is exactly the kind of situation where Greek normally uses the aorist.

So:

• Σφίγγω τη βίδα. = I tighten / I’m tightening the screw.
• Έσφιξα τη βίδα. = I tightened the screw.

Because βίδα is the direct object of the verb, so it must be in the accusative case.

• nominative: η βίδα = the screw
  (used for the subject)
• accusative: τη(ν) βίδα = the screw
  (used for the object)

In this sentence, the screw is what was tightened, so it is the object:

• έσφιξα τη βίδα = I tightened the screw

This is one of the most important case patterns in Greek:

• subject → nominative
• direct object → accusative

Both are possible in principle, but τη βίδα is the normal shortened form before a consonant.

The full accusative feminine article is:

• την

In everyday Modern Greek, the final -ν is often dropped before many consonants:

• τη βίδα
• τη γυναίκα
• τη μέρα

But it is usually kept before vowels and certain consonants, depending on standard spelling rules and pronunciation habits.

So τη βίδα is perfectly normal and standard.

Στο ράφι means on the shelf or at the shelf, depending on context.

It is a contraction of:

• σε + το ράφι → στο ράφι

So:

• σε = in / at / to / on (very broad preposition)
• το ράφι = the shelf
• στο ράφι = on the shelf / at the shelf

Greek σε covers several meanings that English splits into different prepositions. The exact English translation depends on context.

In this sentence, στο ράφι most naturally means that the screw was located on/in the shelf structure or on the shelf.

Usually it is understood as giving the location of the screw or the place where the tightening happened. In practice, those two ideas overlap here.

So:

• τη βίδα στο ράφι can be understood as the screw on/in the shelf
• the whole action also takes place there

Greek often leaves this kind of attachment to context. Native speakers usually understand it easily from the situation.

If you wanted to be more explicit, you could rephrase, but the original sentence is perfectly natural.

Because Greek is expressing an action/state that happened before the past action έσφιξα.

Timeline:

1. the screw had loosened
2. then I tightened it

So Greek uses the pluperfect:

• είχε χαλαρώσει = it had loosened / it had become loose

Compare:

• χαλάρωσε = it loosened
• είχε χαλαρώσει = it had loosened

This matches English very closely here.

It is formed with:

• the imperfect of έχω: είχε = had
• plus the perfective infinitive-like form used in compound tenses: χαλαρώσει

So:

• είχε χαλαρώσει = had loosened

This is the normal way Greek forms the pluperfect.

You will see the same pattern with other verbs:

• είχε φύγει = he/she had left
• είχαν δει = they had seen
• είχα γράψει = I had written

Here it means to become loose / to loosen.

In this sentence:

• είχε χαλαρώσει = it had loosened
  or more naturally in English, it had come loose

This verb can have slightly different meanings depending on context:

• χαλαρώνω = I relax / I loosen
• χαλαρώνει η βίδα = the screw loosens / gets loose

So the same verb can be used:

• transitively: χαλαρώνω τη βίδα = I loosen the screw
• intransitively: η βίδα χαλάρωσε = the screw loosened

That is very common in Greek.

Here γιατί means because.

In Greek, γιατί can mean either:

• why?
• because

Context tells you which one it is.

Examples:

• Γιατί έφυγες; = Why did you leave?
• Έφυγα γιατί κουράστηκα. = I left because I got tired.

In your sentence, it clearly introduces a reason:

• ..., γιατί είχε χαλαρώσει. = ..., because it had loosened.

Because γιατί είχε χαλαρώσει is a subordinate clause giving the reason for the main action.

Main clause:

• Με το κατσαβίδι έσφιξα τη βίδα στο ράφι

Reason clause:

• γιατί είχε χαλαρώσει

Greek punctuation often places a comma before such explanatory or subordinate clauses, especially when they come after the main clause. So the comma here is natural and standard.

Because Greek uses the definite article more often than English does.

So Greek may naturally say:

• with the screwdriver
• the screw
• the shelf

even where English might sometimes prefer:

• with a screwdriver
• a screw
• on a shelf

The Greek sentence sounds like it is referring to specific, identifiable things in the situation:

• the screwdriver being used
• the screw in question
• the shelf involved

This is very normal Greek article usage, and learners should not expect article use to match English one-for-one.

Yes. Greek word order is flexible, and changing it often changes emphasis, not the basic meaning.

For example:

• Με το κατσαβίδι έσφιξα τη βίδα στο ράφι, γιατί είχε χαλαρώσει.
• Έσφιξα τη βίδα στο ράφι με το κατσαβίδι, γιατί είχε χαλαρώσει.
• Τη βίδα στο ράφι την έσφιξα με το κατσαβίδι, γιατί είχε χαλαρώσει.

All of these are possible, though they do not sound exactly the same in emphasis.

The original version highlights the tool used first:

• With the screwdriver, I tightened...

That is why the sentence begins with Με το κατσαβίδι.