Το πλήθος είναι τεράστιο.

• Το = the neuter singular definite article
• πλήθος = a neuter singular noun, meaning crowd, multitude, or large number depending on context
• είναι = is / are, from the verb είμαι (to be)
• τεράστιο = huge / enormous, a neuter singular adjective

So grammatically, the structure is:

The crowd / multitude is huge.

Subject: Το πλήθος
Verb: είναι
Predicate adjective: τεράστιο

Because πλήθος is being used as a specific noun, and Greek normally uses the definite article more often than English does.

Here, το πλήθος means the crowd or the multitude.

The article is το because πλήθος is:

• neuter
• singular
• nominative here

Greek articles must agree with the noun in gender, number, and case.

Because grammatical gender in Greek is a property of the noun itself, and πλήθος happens to be a neuter noun.

This does not mean the thing itself is “neutral” in any real-world sense. It is just the noun class it belongs to.

Since πλήθος is neuter singular, anything agreeing with it must also be neuter singular:

• το πλήθος
• τεράστιο

Because adjectives in Greek agree with the noun they describe.

Since πλήθος is neuter singular, the adjective must also be neuter singular:

• masculine: τεράστιος
• feminine: τεράστια
• neuter: τεράστιο

So:

• ο άνθρωπος είναι τεράστιος = the man is huge
• η πόρτα είναι τεράστια = the door is huge
• το πλήθος είναι τεράστιο = the crowd is huge

Grammatically, πλήθος is singular.

It is a collective noun: it refers to many people or things, but the noun itself is singular, like English crowd.

That is why the verb is singular too:

• Το πλήθος είναι... = The crowd is...

Even though the meaning involves many individuals, Greek treats πλήθος as a singular noun in this sentence.

In Modern Greek, είναι is used for both:

• he/she/it is
• they are

So:

• Το πλήθος είναι τεράστιο = the crowd is huge
• Οι άνθρωποι είναι κουρασμένοι = the people are tired

You tell whether it means is or are from the subject.

Not always. πλήθος can mean several related things depending on context:

• crowd
• multitude
• large number
• sometimes even mass in a more abstract sense

So Το πλήθος είναι τεράστιο could mean:

• The crowd is huge
• The multitude is enormous
• in some contexts, The number is huge

A learner should think of πλήθος as a noun referring to a great number of people or things, with the exact English translation depending on context.

Usually, no. In an ordinary sentence, that would sound unnatural.

Greek normally wants the article here:

• Το πλήθος είναι τεράστιο.

Without the article, it might sound incomplete, literary, or unnatural unless used in a very special context.

So for normal learning purposes, keep το.

Yes. Greek word order is more flexible than English word order.

The neutral, most straightforward version is:

• Το πλήθος είναι τεράστιο.

But you may also hear:

• Τεράστιο είναι το πλήθος.

This changes the emphasis. The second version puts extra focus on τεράστιο.

Still, for a beginner, the basic pattern subject + είναι + adjective is the safest one to use.

A helpful approximation is:

PLEE-thos

More precisely:

• πλ = like pl
• ή = stressed ee
• θ = like th in think
• ος = os

So the stress is on the first syllable:

ΠΛΗ-θος

A helpful approximation is:

te-RA-sti-o

The stress is on ρά:

• τε = te
• ρά = RA
• στι = sti
• ο = o

So:

τε-ΡΑ-στι-ο

In normal speech, the last two vowels are often said smoothly, but as a learner it is fine to pronounce all parts clearly.

Because in Modern Greek, several different spellings are pronounced the same way, as /i/.

For example, all of these can sound like ee:

• ι
• η
• υ
• ει
• οι
• υι

So:

• πλήθος has ή pronounced ee
• είναι has εί also pronounced ee

The spelling is historical, but the pronunciation in Modern Greek is the same sound.

It is in the nominative case, because it is the subject of the sentence.

• Το πλήθος = the subject
• είναι = the verb
• τεράστιο = predicate adjective describing the subject

So this is a basic nominative subject + to be + adjective structure.

It is an adjective.

It describes the noun πλήθος, even though it comes after the verb είναι.

This is the same idea as in English:

• The crowd is huge

Here, huge is still an adjective, not an adverb.

In Greek, adjectives can appear:

• before the noun: το τεράστιο πλήθος
• after είναι: το πλήθος είναι τεράστιο

Both are adjectives; the second one is a predicate adjective.

They are related, but not identical.

• το τεράστιο πλήθος = the huge crowd

  • adjective directly attached to the noun inside the noun phrase

• το πλήθος είναι τεράστιο = the crowd is huge

  • full sentence with the verb is

So:

• one is a noun phrase
• the other is a complete sentence

Yes, accents matter in written Greek because they show where the stress goes.

• πλήθος → stress on πλή
• είναι → stress on εί
• τεράστιο → stress on ρά

For a learner, this is important because wrong stress can make your Greek sound unnatural and can sometimes cause confusion.

So it is a good habit to learn words together with their accents.