الملمس أملس.

Because Arabic often uses a nominal sentence in the present tense, with no separate word for is/are.

So:

• الملمس أملس = The texture is smooth

This is completely normal in MSA.
If you wanted was, you would use كان; if you wanted will be, you would use سيكون.

Because the two words are doing different jobs:

• الملمس = the subject, the texture
• أملس = the predicate, smooth

In Arabic, when an adjective is used as the predicate of a sentence, it is usually indefinite:

• الملمس أملس = The texture is smooth

But if the adjective were directly modifying the noun inside one noun phrase, it would match in definiteness:

• الملمس الأملس = the smooth texture

That is a very important distinction in Arabic.

Yes. أملس is an adjective meaning smooth.

In this sentence, it functions as the predicate of the nominal sentence. So even though it is an adjective, it is not attached to the noun as a direct modifier; instead, it tells you something about the subject:

• الملمس = the texture
• أملس = smooth

So the structure is basically:

• subject + predicate

not:

• noun + adjective phrase

Because it is not an attributive adjective here; it is a predicate adjective.

Compare:

• الملمس أملس = The texture is smooth

  • sentence
  • أملس is a predicate

• الملمس الأملس = the smooth texture

  • noun phrase
  • الأملس is a regular modifying adjective

English uses the same word smooth in both cases, but Arabic shows the difference more clearly.

Yes, in gender and number.

Here, الملمس is masculine singular, so the predicate is also masculine singular:

• الملمس أملس

But definiteness is different, because again, أملس is a predicate, not an attributive adjective.

For example, with a feminine singular noun, you would use the feminine form:

• البشرة ملساء = The skin is smooth

So the agreement rules are there, but not in exactly the same way as in a noun + adjective phrase.

A careful formal pronunciation with case endings is:

• al-malmasu amlasu

In normal pause at the end of a sentence, the short final vowels are often not pronounced, so you may hear something closer to:

• al-malmas amlas

Also note that أملس begins with a pronounced hamza sound, so it starts with a clear a sound: amlas.

In a basic nominal sentence, both the subject and the predicate are in the nominative.

So, fully vocalized, the sentence is:

• اَلْمَلْمَسُ أَمْلَسُ

That means:

• الملمسُ = nominative subject
• أملسُ = nominative predicate

In everyday Arabic writing, these endings are usually omitted, so you normally just see:

• الملمس أملس

This is a more advanced point: أملس is on the pattern أفعل, and adjectives of this type are often diptotes.

That means in the nominative they take:

• ـُ
  not
• ـٌ

So the fully vowelled form is:

• أملسُ not
• أملسٌ

You do not need this point to understand the sentence, but it explains why a grammar book may show a single ḍamma instead of tanwīn.

It is pronounced normally as al-, because م is a moon letter, not a sun letter.

So you say:

• al-malmas

not:

• am-malmas

This is because the l of الـ is only assimilated before sun letters, and م is not one of them.

Its root is ل-م-س, which is connected with touching or feeling by touch.

So ملمس refers to texture, feel, or surface feel — basically, how something feels when touched.

The initial م is part of the noun pattern, not part of the root.

You would add a form of كان:

• كان الملمس أملسَ = The texture was smooth
• سيكون الملمس أملسَ = The texture will be smooth

Notice that after كان and its sisters, the predicate becomes accusative, so أملس would be أملسَ in full vocalization.

So the simple sentence الملمس أملس is specifically the normal present-time way to say The texture is smooth.

Sometimes yes, but the nuance is a little different.

• أملس focuses on being smooth, not rough, even-surfaced
• ناعم often suggests soft, fine, or pleasantly smooth

So:

• الملمس أملس = the texture is smooth
• الملمس ناعم = the texture is soft/smooth

In many contexts both are possible, but أملس is the more exact word for a smooth, non-rough surface.