הזנב ארוך.

In the present tense, Hebrew usually does not use a word for is / are / am.

So:

• הזנב ארוך = The tail is long
• literally, it is more like the tail long

This is a very normal Hebrew sentence pattern.
In past or future tense, Hebrew does use forms of to be:

• הזנב היה ארוך = The tail was long
• הזנב יהיה ארוך = The tail will be long

The prefix ה־ is the Hebrew definite article, meaning the.

So:

• זנב = a tail / tail
• הזנב = the tail

It is attached directly to the noun, not written as a separate word.

In Hebrew, adjectives normally come after the noun they describe.

So:

• זנב ארוך = a long tail
• literally: tail long

This is the normal Hebrew order, unlike English, where adjectives usually come before the noun.

Because ארוך here is a predicate adjective, not an adjective directly attached inside a noun phrase.

Compare these two:

• זנב ארוך = a long tail
• הזנב ארוך = the tail is long

In הזנב ארוך, הזנב is the subject, and ארוך is saying something about it. Predicate adjectives in Hebrew do not take ה־.

But if the adjective is part of a noun phrase, it does match definiteness:

• הזנב הארוך = the long tail

So this is an important contrast:

• הזנב ארוך = The tail is long
• הזנב הארוך = the long tail

זנב is masculine singular, so the adjective must also be masculine singular.

That is why the sentence uses:

• ארוך = masculine singular long

Hebrew adjectives agree with the noun in:

• gender
• number
• sometimes definiteness, depending on the structure

For comparison:

• זנב ארוך = a long tail
• זנבות ארוכים = long tails

The adjective would change to the feminine form.

For long, the forms are:

• masculine singular: ארוך
• feminine singular: ארוכה

So if you had a feminine singular noun, you would use ארוכה instead.

Example:

• הדלת ארוכה = The door is long

This helps show that ארוך in your sentence is specifically matching a masculine singular noun.

A common pronunciation is:

• ha-zanáv arókh

A rough guide for an English speaker:

• הזנב = ha-za-NAV
• ארוך = a-ROKH

Notes:

• The ch sound in arókh is like the sound in German Bach or Scottish loch, not like English ch in chair.
• Stress is usually on the last syllable in both words here.

You would say:

• זנב ארוך

This is a noun phrase, not a full sentence.

So compare:

• זנב ארוך = a long tail
• הזנב ארוך = The tail is long

That difference is very useful in Hebrew:

• no ה־ on the noun: often a/an
• definite noun + adjective without ה־ on the adjective: often a full sentence like is long

You would say:

• הזנב הארוך

Here both the noun and the adjective take ה־ because the whole noun phrase is definite.

Compare all three:

• זנב ארוך = a long tail
• הזנב הארוך = the long tail
• הזנב ארוך = The tail is long

These three patterns are extremely important in Hebrew.

Yes. הזנב ארוך is a complete and natural Hebrew sentence.

Hebrew often forms present-tense sentences with:

• a subject
• plus a noun/adjective phrase

without using a separate verb for is.

So even though it is only two words, it is fully complete:

• הזנב = the subject
• ארוך = what is being said about it

That is enough to make a full sentence in Hebrew.