Η μαμά θέλει να έχεις πάρει το πατίνι και τον χαρταετό από το αυτοκίνητο πριν φύγετε για το πάρκο.

Because να έχεις πάρει is the perfect subjunctive, and it emphasizes that the action must be completed before something else happens.

• να πάρεις = to take / that you take
• να έχεις πάρει = to have taken

In this sentence, the mother does not just want the action to happen at some point. She wants it to be already done before you leave:

• Η μαμά θέλει να έχεις πάρει... πριν φύγετε...
• Mom wants you to have taken ... before you leave ...

So Greek uses the perfect form here to show completed action before another future action.

It has three parts:

• να = subjunctive marker
• έχεις = you have
• πάρει = participle-like perfect form of παίρνω (take)

So:

• να έχεις πάρει = that you have taken / to have taken

This is the normal way Greek forms the perfect subjunctive:

• να
  • form of έχω
    • perfect stem/form of the verb

For example:

• να έχεις φύγει = to have left
• να έχεις δει = to have seen

Because πάρει here is not the simple subjunctive form. It is part of the perfect construction.

Compare:

• να πάρεις = simple subjunctive, that you take
• να έχεις πάρει = perfect subjunctive, that you have taken

So once you use έχεις, the main verb changes to πάρει, not πάρεις.

No, it is not a mistake. The sentence switches from singular you to plural you.

• να έχεις πάρει = you singular
• πριν φύγετε = you all plural

This suggests a situation like:

• Mom is speaking to one person
• but the leaving is something more than one person will do together

So the meaning is something like:

• Mom wants you (one person) to have taken the scooter and the kite from the car before you all leave for the park.

This kind of switch is completely possible in Greek.

Because after πριν (before), Greek often uses the subjunctive verb without repeating να.

So:

• πριν φύγετε = before you leave

This is normal Greek structure.

Compare:

• Θέλω να φας πριν φύγεις.
• I want you to eat before you leave.

Even though φύγεις / φύγετε is subjunctive in meaning, να is usually not stated after πριν.

φύγετε is the aorist subjunctive, 2nd person plural, of φεύγω (leave).

Here it means:

• before you all leave

Greek often uses the aorist subjunctive after words like πριν when referring to a single complete action.

So:

• πριν φύγετε = before you leave

Because the nouns have different genders, and Greek articles must agree with the noun.

• το πατίνι = neuter
• ο χαρταετός = masculine

In the sentence, both nouns are direct objects, so they are in the accusative case:

• neuter accusative singular: το πατίνι
• masculine accusative singular: τον χαρταετό

So the different articles are just normal gender-and-case agreement.

The dictionary form is:

• ο χαρταετός = the kite

But in the sentence it is a direct object, so it changes to the accusative:

• nominative: ο χαρταετός
• accusative: τον χαρταετό

This is very common with masculine nouns ending in -ος:

• ο φίλος → τον φίλο
• ο δρόμος → τον δρόμο
• ο χαρταετός → τον χαρταετό

So χαρταετό is just the accusative form.

It means from the car or more naturally in English, out of the car.

• από = from
• το αυτοκίνητο = the car

In this context, it means the scooter and the kite are in the car, and someone needs to bring them out.

So:

• να έχεις πάρει ... από το αυτοκίνητο
• to have taken ... out of the car

Because για often expresses destination or purpose, especially in expressions like leave for a place.

• για το πάρκο = for the park / to the park
• στο πάρκο = to the park / at the park, depending on context

With φεύγω, both types of expressions can exist, but φεύγω για... is very natural when you mean set off for or leave headed toward a place.

So:

• φεύγετε για το πάρκο = you are leaving for the park

This sounds very natural in Greek.

Yes, structurally that is close.

Greek often uses:

• θέλω να + verb

So:

• Η μαμά θέλει να έχεις πάρει...
• literally: Mom wants that you have taken...
• natural English: Mom wants you to have taken...

Greek uses να-clauses in many places where English prefers an infinitive or an object + infinitive structure.

Yes, but the meaning would change.

• Η μαμά θέλει να έχεις πάρει... = Mom wants you to have taken...
• Πρέπει να έχεις πάρει... = You must have taken... or in some contexts You must take...

So θέλει gives the idea of someone's wish or instruction, while πρέπει gives a stronger sense of necessity/obligation.

Here, θέλει sounds like the mother's requirement or expectation.

The word order is natural, but Greek is more flexible than English.

Original:

• Η μαμά θέλει να έχεις πάρει το πατίνι και τον χαρταετό από το αυτοκίνητο πριν φύγετε για το πάρκο.

This order is clear and smooth:

1. who wants something
2. what must be done
3. from where
4. before what event

Greek could rearrange parts for emphasis, but the original is a very normal order.

Probably the combination of two things:

1. The perfect subjunctive

   • να έχεις πάρει
   • this expresses completed action

2. The change from singular to plural you

   • έχεις = you singular
   • φύγετε = you all plural

So a learner has to notice both the tense/aspect meaning and the subject change. Once you see those, the sentence becomes much easier to understand.