Tessera quadrata est.

The subject is tessera. The verb is est, which means is.

So the basic structure is:

• tessera = the thing being talked about
• quadrata = square
• est = is

In other words, Tessera quadrata est means The tessera is square or A tessera is square, depending on context.

Because it has to agree with tessera.

In Latin, adjectives agree with the nouns they describe in:

• gender
• number
• case

Tessera is a feminine singular nominative noun, so the adjective must also be feminine singular nominative. That is why Latin uses quadrata, not quadratus or quadratum.

A very important beginner rule is:

• feminine noun → feminine adjective form
• masculine noun → masculine adjective form
• neuter noun → neuter adjective form

Tessera is in the nominative singular.

You can tell this because it is the subject of the sentence. In Latin, the subject of a finite verb is normally in the nominative case.

Here, tessera is the thing that is square, so it is the subject, and therefore nominative.

Also, tessera is a first-declension noun, and -a is a very common nominative singular ending for first-declension feminine nouns.

Here, quadrata is being used as an adjective meaning square.

Historically, it is related to a participial form, but for a beginner reading this sentence, the important point is simple:

• quadrata describes tessera
• it means square
• it agrees with tessera

So in this sentence, you can safely treat it as an ordinary adjective.

Because Latin word order is much more flexible than English word order.

English strongly prefers:

• The tessera is square

Latin can do that, but it often puts the verb later, especially in simple statements:

• Tessera quadrata est

This is perfectly normal Latin.

Latin uses endings more than word order to show how words fit together, so the meaning stays clear even when the order changes.

For example, these can all mean roughly the same thing:

• Tessera quadrata est
• Tessera est quadrata
• Quadrata tessera est

The differences are mostly about emphasis or style, not basic meaning.

Because Latin does not have articles like English the and a/an.

So tessera can mean:

• a tessera
• the tessera

You decide which English translation sounds right from the context.

That is very normal in Latin. A noun by itself often has to be translated with either the or a/an, even though no separate Latin word is present.

This is a sentence with a linking verb.

The verb est links the subject tessera with a word that describes it, quadrata.

So the pattern is:

• subject
  • predicate adjective
    • linking verb

In English:

• The tessera is square

In Latin:

• Tessera quadrata est

This is not an action sentence like The girl carries water. It is a description sentence: it tells you what the subject is like.

Sometimes Latin can omit a form of to be, especially in poetry, headings, very compressed style, or certain expressions. But for a basic prose sentence like this, est is normally included.

So for a learner, the safest understanding is:

• Tessera quadrata est = normal full sentence
• est is doing important work and should be translated as is

Do not assume you can freely drop est in ordinary beginner Latin sentences.

Tessera is a first-declension noun.

Its dictionary form would typically be:

• tessera, tesserae f.

That tells you it is feminine and first declension.

Quadrata comes from the adjective quadratus, -a, -um, which is a first-and-second-declension adjective.

That means its endings change like this in the nominative singular:

• quadratus = masculine
• quadrata = feminine
• quadratum = neuter

Since tessera is feminine, Latin uses quadrata.

A common reconstructed Classical pronunciation would be approximately:

• TES-se-ra kwa-DRA-ta est

A few helpful points:

• tessera has a double ss, so the s is pronounced clearly
• qu is pronounced like kw
• quadrata has the stress on dra
• est is pronounced with a clear e, not like English is

So the whole sentence sounds roughly like:

• TES-se-ra kwa-DRA-ta est

Yes. That is one of the most important features of Latin grammar.

The adjective must match the noun in gender, number, and case.

For example:

• murus quadratus est = the wall is square
  (murus is masculine, so quadratus is masculine)

• templum quadratum est = the temple is square
  (templum is neuter, so quadratum is neuter)

• tessera quadrata est = the tessera is square
  (tessera is feminine, so quadrata is feminine)

This matching is called agreement, and it is a central idea in Latin.