Ο αγοραστής περιμένει.

Ο is the Greek definite article, meaning the here. It is capitalized only because it begins the sentence. In the middle of a sentence, it would normally be ο.

In this sentence, ο is the masculine singular nominative form of the.

αγοραστής is in the nominative singular. That is the case normally used for the subject of the sentence.

Here, ο αγοραστής is the subject, so Greek uses the nominative:

• ο αγοραστής = the buyer as the subject

Yes. αγοραστής is a grammatically masculine singular noun, which matches the article ο.

Depending on context, it may refer to a male buyer specifically, or sometimes be used in a more general sense. If Greek wants to refer specifically to a female buyer, it would normally use a feminine form instead.

The ending -ής is a common ending for masculine nouns, especially nouns referring to a person or role.

So when you see αγοραστής, a useful first guess is:

• it is a masculine singular noun
• it probably refers to a person

You still need context and the article to be sure of its exact grammatical role, but the ending gives a strong clue.

The dictionary form is περιμένω.

Greek dictionaries usually list verbs in the first person singular present form, so:

• περιμένω = I wait / I am waiting
• περιμένει = he/she/it waits / is waiting

The ending -ει shows that the verb is third person singular in the present tense.

So περιμένει means:

• he waits
• she waits
• it waits
• or, with a noun subject like here, the buyer waits / is waiting

Because ο αγοραστής is singular, the verb is singular too.

It can mean either one, depending on context.

Greek present tense often covers both:

• a simple present meaning: waits
• a present continuous meaning: is waiting

So Ο αγοραστής περιμένει. could be:

• The buyer waits.
• The buyer is waiting.

English chooses between those more often than Greek does.

Greek often leaves out subject pronouns because the verb ending already gives person and number.

In περιμένει, the ending already tells you it is third person singular. And in this sentence, the subject is stated explicitly anyway: ο αγοραστής.

So Greek does not need to add a separate word for he.

Yes, that is grammatical.

Greek word order is more flexible than English. The neutral order here is subject + verb:

• Ο αγοραστής περιμένει.

But you can also say:

• Περιμένει ο αγοραστής.

That may sound more marked, depending on context, and can shift emphasis slightly. English usually cannot change word order this freely without sounding unusual.

In a normal sentence, you would usually keep the article: ο αγοραστής.

Greek uses the definite article more regularly than English in many ordinary noun phrases. Without the article, αγοραστής περιμένει would sound unnatural in ordinary prose, or more like a headline, label, or very special style.

So for a normal sentence meaning the buyer is waiting, Ο αγοραστής περιμένει is the natural form.

Yes. Just like English is waiting, Greek περιμένει can stand on its own.

If you want, you can also add what is being waited for:

• Ο αγοραστής περιμένει το λεωφορείο. = The buyer is waiting for the bus.

So the short sentence is complete by itself.

A simple pronunciation guide is:

• Ο = o
• αγοραστής = a-go-ra-STIS
• περιμένει = pe-ri-ME-ni

The stress falls where the accent marks show it:

• αγοραστής
• περιμένει

A rough IPA pronunciation is: [o aɣoraˈstis periˈmeni]

For an English speaker, the main things to notice are:

• ει is pronounced like ee
• the accent mark shows which syllable is stressed

The accent marks show which syllable is stressed when you pronounce the word.

So:

• αγοραστής is stressed on the last syllable
• περιμένει is stressed on μέ

They are not optional in normal Greek writing. They are an important part of the spelling.