الضوافر طويلة.

Because Arabic usually leaves out the present-tense verb to be in simple sentences like this.

So:

• الضوافر طويلة = The nails are long

There is no separate word for are in the present tense here.

If you wanted the past, you would use a verb, for example:

• الضوافر كانت طويلة = The nails were long

This kind of sentence is very common in both Egyptian Arabic and Standard Arabic.

This is one of the most important patterns to learn.

In Arabic, non-human plural nouns often take feminine singular agreement. Since الضوافر refers to things, not people, the adjective is طويلة and not a plural form.

So the pattern is:

• الضوافر طويلة
• literally something like the nails long-feminine singular

Even though it sounds strange from an English point of view, this is normal Arabic grammar.

A useful comparison:

• البنات طويلين / طوال = The girls are tall
  Here the noun is human, so plural agreement is used.

But:

• العربيات كبيرة = The cars are big
• الضوافر طويلة = The nails are long

Both cars and nails are non-human plurals, so the adjective is feminine singular.

Because in Arabic, adjectives normally come after the noun they describe.

So:

• ضوافر طويلة = long nails
• literally nails long

This is the normal order in Arabic, unlike English.

In your sentence, طويلة is functioning as the predicate of the sentence, but it still comes after the noun:

• الضوافر طويلة = The nails are long

So for an English speaker, it helps to get used to the idea that Arabic usually says noun + adjective, not adjective + noun.

Because this sentence means The nails are long, not the long nails.

This is a very important distinction:

• الضوافر طويلة = The nails are long
• الضوافر الطويلة = the long nails

So:

• definite noun + adjective without الـ often gives a full sentence
• definite noun + definite adjective gives a noun phrase

That means the presence or absence of الـ changes the structure:

• الضوافر طويلة = a complete statement
• الضوافر الطويلة = just a phrase

In Egyptian Arabic, الـ is often pronounced el- or il-, but with some letters the l sound blends into the next consonant.

Since ض is one of those letters, الضوافر is pronounced roughly:

• eḍ-ḍawāfer

You may also hear learners write it approximately as:

• ed-dawāfer

But the more accurate sound uses an emphatic ḍ sound, because the first letter is ض.

So the whole sentence is roughly:

• eḍ-ḍawāfer ṭawīla

ضوافر is common in Egyptian Arabic.

In Standard Arabic, the usual word is:

• أظافر

So in Standard Arabic, the sentence would usually be:

• الأظافر طويلة

The grammar is basically the same:

• no present-tense are
• non-human plural with feminine singular adjective

So the main difference here is mostly the word choice and pronunciation, not the sentence structure.

Usually it just means nails in general. Context tells you whether someone means fingernails or toenails.

If the situation is clear, Arabic often does not specify more than English does.

If you really need to be specific, speakers can say something like:

• ضوافر الإيد = fingernails
• ضوافر الرجل = toenails

But by itself, الضوافر can refer to either.

The singular in Egyptian Arabic is usually:

• ضافر = a nail

Since ضافر is singular, the adjective changes too:

• الضافر طويل = The nail is long

Notice the difference:

• الضافر طويل = singular noun, masculine singular adjective
• الضوافر طويلة = plural non-human noun, feminine singular adjective

So this sentence is a good example of how Arabic agreement changes depending on whether the noun is singular or non-human plural.