Ποιο είναι το συνώνυμο της λέξης «ωραίος»;

Literally, ποιο is the neuter form of which. In this sentence, though, English usually translates it more naturally as what:

• Ποιο είναι το συνώνυμο... = What is the synonym...

So a very literal gloss is something like Which is the synonym..., but the normal English translation is What is the synonym...?

Because ποιο agrees with το συνώνυμο, and συνώνυμο is a neuter noun in Greek.

The forms are:

• ποιος = masculine
• ποια = feminine
• ποιο = neuter

Since the sentence asks about the synonym — το συνώνυμο — Greek uses the neuter form ποιο.

It is in the nominative singular.

That is the basic dictionary form of the noun:

• το συνώνυμο = the synonym

With the verb είναι (is), Greek often uses the nominative in this kind of identifying sentence.

Because Greek uses the genitive to express of the word.

• η λέξη = the word
• της λέξης = of the word

So:

• το συνώνυμο της λέξης = the synonym of the word

This is a very common Greek pattern:
noun + genitive = noun of noun

Because λέξη is a feminine noun, and here it has to be in the genitive singular after της.

Its forms are:

• η λέξη = the word
• της λέξης = of the word

So the ending changes because the grammatical role changes.

Because ωραίος is being mentioned as a word, not used normally inside the grammar of the sentence.

In other words, the sentence is talking about the word ωραίος itself. When Greek cites a word like that, it usually keeps the word in its citation form, instead of declining it to fit the surrounding sentence.

Also, ωραίος is the usual dictionary form of the adjective:

• ωραίος = masculine
• ωραία = feminine
• ωραίο = neuter

So here Greek is treating ωραίος as a lexical item being named.

Greek uses the definite article very often, more often than English does.

Here:

• το συνώνυμο = the synonym
• της λέξης = of the word

In English, article use can sometimes be looser in dictionary-style questions, but in Greek the articles sound normal and expected.

Those marks show that ωραίος is being cited as a word.

Greek often uses guillemets — « » — where English might use quotation marks. Here they help signal:

• we are not using ωραίος as an adjective in the sentence
• we are talking about the word ωραίος itself

Because in Greek, ; is the question mark.

So:

• Greek ; = English ?

This is one of the first punctuation differences learners notice.

A rough English-style pronunciation is:

PYO EE-ne to see-NO-nee-mo tees LEK-sees o-RE-os?

A few notes:

• Ποιο is roughly PYO
• είναι is roughly EE-ne
• συνώνυμο has the stress on νώ
• λέξης has the stress on λέ
• ωραίος is roughly o-RE-os

This order is the most neutral and natural:

• Ποιο είναι το συνώνυμο της λέξης ωραίος;

Greek word order is more flexible than English word order, but this version is the standard way to ask the question.

If you changed the order, the sentence might sound more marked, more literary, or more emphatic.

Yes. You could also say:

• Ποιο είναι ένα συνώνυμο της λέξης ωραίος;

That means What is a synonym of the word ωραίος?

The difference is:

• το συνώνυμο = the synonym / the synonym being asked for in a general sense
• ένα συνώνυμο = a synonym / one possible synonym

Since a word can have more than one synonym, ένα συνώνυμο can be very natural too.