Ο παππούς μου πίνει μόνο νερό, αλλά η γιαγιά μου ζητάει πάντα λίγο παγωτό ή λεμονάδα το καλοκαίρι.

Greek normally uses the definite article with nouns much more often than English does.

So:

• ο παππούς μου = my grandfather
• η γιαγιά μου = my grandmother

This is completely normal Greek. The article shows the noun’s gender, number, and case:

• ο = masculine singular nominative
• η = feminine singular nominative

You will also see this with names and family words very often in Greek.

In Greek, the unstressed possessive form μου usually comes after the noun.

So:

• ο παππούς μου = my grandfather
• η γιαγιά μου = my grandmother

This is the standard pattern. English says my + noun, but Greek often says the noun + my.

Other examples:

• το σπίτι μου = my house
• η αδερφή μου = my sister

Greek often drops subject pronouns because the verb ending already tells you the person and number.

Here:

• πίνει = he/she drinks
• ζητάει = he/she asks for / wants / orders

Since the subjects are already named:

• Ο παππούς μου πίνει...
• η γιαγιά μου ζητάει...

there is no need to add αυτός or αυτή.

This is very common in Greek.

They are completely different words:

• η = the for feminine singular nouns
• ή = or

So in the sentence:

• η γιαγιά μου = my grandmother
• παγωτό ή λεμονάδα = ice cream or lemonade

The accent mark is important here. Without it, η is the article; with it, ή is the conjunction or.

Yes. They are two different verbs with different present-tense patterns.

• πίνω = I drink → πίνει = he/she drinks
• ζητάω / ζητώ = I ask for / seek → ζητάει = he/she asks for

With ζητάω, Greek allows more than one common present form:

• ζητάει
• ζητά

Both are standard in everyday Greek. ζητάει is just a fuller form of the same verb.

So this is not a special meaning difference; it is mainly a matter of verb pattern and style.

Literally, ζητάει means something like asks for, requests, or seeks.

In a sentence about food or drink, it often feels natural in English as:

• asks for
• orders
• sometimes even wants

So here it suggests that the grandmother typically asks for or orders a little ice cream or lemonade in summer.

It does not mean a deep emotional want in the same way as θέλει, although in context the meanings can overlap a bit.

μόνο means only, and here it directly emphasizes νερό:

• πίνει μόνο νερό = he drinks only water

That is the most natural placement if the idea is that water is the only thing he drinks.

Greek word order is fairly flexible, but position affects emphasis. For example:

• Ο παππούς μου μόνο νερό πίνει gives stronger emphasis to only water

The sentence you have is the neutral, natural version.

Because these nouns are being used in a general, indefinite sense, much like English:

• drinks water
• asks for some ice cream
• or lemonade

Greek often leaves out the article with mass nouns or indefinite food/drink nouns when the meaning is general or non-specific.

Compare:

• πίνει νερό = he drinks water
• πίνει το νερό = he drinks the water (a specific water, for example the water on the table)

So the lack of an article here is normal.

That is a very good question, because λεμονάδα is feminine, so by itself you would normally expect:

• λίγη λεμονάδα = a little lemonade

And you would also say:

• λίγο παγωτό = a little ice cream

In the sentence, λίγο appears only once before the whole pair:

• λίγο παγωτό ή λεμονάδα

This is a natural kind of shortcut in coordination. The λίγο is understood with both items, even though it matches the first noun παγωτό.

A fuller version would be:

• λίγο παγωτό ή λίγη λεμονάδα

So the sentence is understandable and natural, but if you wanted to show agreement very clearly with each noun, you could repeat the word.

Here λίγο means a little, a small amount of, or sometimes simply some.

So:

• λίγο παγωτό = a little ice cream / some ice cream

It is often used with food, drink, and mass nouns:

• λίγο νερό = a little water
• λίγη ζάχαρη = a little sugar
• λίγο ψωμί = a little bread

It helps make the request sound moderate or natural.

Greek often uses the definite article in time expressions, especially with seasons.

So:

• το καλοκαίρι = in summer / during the summer
• τον χειμώνα = in winter
• την άνοιξη = in spring

This is a very common Greek pattern. English usually uses in, but Greek often just uses the article plus the time word.

In this sentence, το καλοκαίρι means during the summer or in summertime.

It is most naturally understood as a habitual statement.

The present tense in Greek can describe either:

• something happening now, or
• a general habit / repeated action

Here the words πάντα (always) and το καλοκαίρι (in summer) clearly push the meaning toward habit:

• the grandfather habitually drinks only water
• the grandmother habitually asks for a little ice cream or lemonade in summer

So this is not mainly a one-time event.

Greek word order is more flexible than English word order, because endings and articles help show what each word is doing.

The original sentence is a neutral, natural order:

• Ο παππούς μου πίνει μόνο νερό, αλλά η γιαγιά μου ζητάει πάντα λίγο παγωτό ή λεμονάδα το καλοκαίρι.

But Greek could rearrange parts of it for emphasis. For example:

• Μόνο νερό πίνει ο παππούς μου...
• Η γιαγιά μου πάντα ζητάει...
• Το καλοκαίρι η γιαγιά μου ζητάει...

These all shift the emphasis slightly.

So the order is not completely fixed, but the version you have is a very standard one for learners to follow.