Στην αυλή της γιαγιάς μου πίνουμε καφέ το πρωί.

Στην is the usual contracted form of σε + την.

• σε = in / at / to
• την = the feminine singular accusative article

So:

• σε την αυλή → στην αυλή

This contraction is extremely common in everyday Greek.

Examples:

• στο σπίτι = σε το σπίτι
• στην πόρτα = σε την πόρτα

After σε (and therefore after στην), the noun usually goes in the accusative case.

So in this sentence:

• η αυλή = the courtyard / yard (nominative)
• την αυλή = the courtyard / yard (accusative)

Because the phrase means in the courtyard, Greek uses:

• στην αυλή

This is normal after many prepositions in Modern Greek.

Greek often expresses possession with a genitive phrase plus a possessive pronoun.

Break it down:

• της γιαγιάς = of the grandmother
• μου = my

Together:

• της γιαγιάς μου = of my grandmother / my grandmother’s

So the structure is literally something like:

• the courtyard of my grandmother

This is a very natural Greek way to say possession.

Because γιαγιάς is the genitive singular form of η γιαγιά.

Forms:

• η γιαγιά = the grandmother (nominative)
• της γιαγιάς = of the grandmother (genitive)

Since the sentence means my grandmother’s courtyard, Greek needs the genitive:

• της γιαγιάς μου

In Greek, nouns usually keep their article even inside possession phrases.

So Greek says:

• της γιαγιάς μου = of my grandmother

not normally just:

• γιαγιάς μου

The article is an important part of the noun phrase in Greek and appears much more often than English learners may expect.

Πίνουμε means we drink.

Greek verbs usually include the subject inside the verb ending, so the subject pronoun is often omitted.

• πίνω = I drink
• πίνεις = you drink
• πίνει = he/she/it drinks
• πίνουμε = we drink

So Greek does not need εμείς here.
If you added εμείς, it would sound more emphatic:

• Εμείς πίνουμε καφέ... = We drink coffee... (with emphasis on we)

Because καφέ here is a general, indefinite object: we drink coffee.

In Greek, when talking about a substance or a general activity, the noun often appears without an article:

• πίνουμε καφέ = we drink coffee
• πίνω νερό = I drink water
• τρώμε ψωμί = we eat bread

If you wanted to mean a coffee, you could say:

• πίνουμε έναν καφέ

That sounds more like we have a coffee / one coffee.

Greek often uses the article in time expressions.

So:

• το πρωί = in the morning
• το βράδυ = in the evening / at night
• το απόγευμα = in the afternoon

Even though English does not use the here, Greek normally does.

This is a very common pattern, so it is best learned as a set phrase:

• το πρωί = in the morning

It functions as an adverbial expression of time.

It tells you when the action happens:

• πίνουμε καφέ = we drink coffee
• το πρωί = in the morning

So the sentence answers both:

• Where? → Στην αυλή της γιαγιάς μου
• When? → το πρωί

Greek word order is more flexible than English word order.

The sentence:

• Στην αυλή της γιαγιάς μου πίνουμε καφέ το πρωί.

is perfectly natural, but other orders are also possible, depending on emphasis:

• Πίνουμε καφέ στην αυλή της γιαγιάς μου το πρωί.
• Το πρωί πίνουμε καφέ στην αυλή της γιαγιάς μου.
• Καφέ πίνουμε το πρωί στην αυλή της γιαγιάς μου. (stronger emphasis on coffee)

Even when the order changes, the endings and articles help show how the words fit together.

It can mean different things depending on context.

Since στην comes from σε + την, it can be translated as:

• in
• at
• to

Examples:

• στην αυλή = in the courtyard
• στην τάξη = in class / in the classroom
• στην Αθήνα = to Athens / in Athens, depending on context

In your sentence, because the action is happening there, στην αυλή means in the courtyard / in the yard.

Greek uses articles much more often than English.

In this sentence:

• στην αυλή = in the courtyard
• της γιαγιάς μου = of my grandmother
• το πρωί = in the morning

English often leaves articles out in places where Greek requires them, especially:

• in possession phrases
• in time expressions
• with prepositional phrases

So although it may feel heavy to an English speaker, this is very normal Greek.

No, that word order is not correct.

The natural order is:

• της γιαγιάς μου

First comes the article + noun phrase in the genitive, and then the possessive pronoun:

• της αδερφής μου = my sister’s / of my sister
• του πατέρα μου = my father’s / of my father
• της γιαγιάς μου = my grandmother’s / of my grandmother

So in your sentence, the correct phrase is:

• Στην αυλή της γιαγιάς μου

It can be translated as either, depending on context.

η αυλή usually refers to an outdoor area belonging to a house, school, or building, such as:

• yard
• courtyard

So in this sentence, both yard and courtyard are possible translations depending on the image you have in mind. Greek itself does not force a sharp distinction here.