الدواسة صغيرة.

A common careful pronunciation is:

ad-dawwāsatu ṣaghīratun

In normal pause, many final short vowels are dropped, so you will often hear something closer to:

ad-dawwāsa ṣaghīra

A few pronunciation notes:

• ال before د is pronounced ad-, not al-, because د is a sun letter.
• وّا gives a doubled w sound: daw-wā.
• ص is an emphatic s sound, deeper than plain س.
• غ is a throaty sound, like a French or German r in many accents.

ال is the Arabic definite article, meaning the.

So:

• دواسة = a pedal / pedal
• الدواسة = the pedal

In this sentence, the noun is definite: the pedal.

In Arabic, the verb to be is usually not written or spoken in the present tense in simple sentences like this.

So:

• الدواسة صغيرة literally looks like the pedal small
• but it means The pedal is small

This is completely normal in Arabic.
If you wanted a past or future meaning, Arabic would use a verb:

• كانت الدواسة صغيرة = The pedal was small
• ستكون الدواسة صغيرة = The pedal will be small

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

So:

• الدواسة الصغيرة = the small pedal

This is the normal noun + adjective order in Arabic.

In your sentence, though, صغيرة is not just an adjective inside a noun phrase. It is the predicate of the sentence:

• الدواسة صغيرة = The pedal is small

So even though the English translation uses is, Arabic simply puts the description after the noun.

Because الدواسة is feminine, and Arabic adjectives must agree with the noun in gender.

So:

• masculine: صغير = small
• feminine: صغيرة = small

Since الدواسة is feminine, the adjective must also be feminine:

• الدواسة صغيرة

A strong clue is the ـة at the end of دواسة, which often marks a feminine noun.

This is a very important point.

In الدواسة صغيرة, صغيرة is the predicate of the sentence, not an attributive adjective directly attached to the noun.

So:

• الدواسة صغيرة = The pedal is small
• الدواسة الصغيرة = the small pedal

Compare them:

1. الدواسة صغيرة

   • full sentence
   • noun + predicate
   • means The pedal is small

2. الدواسة الصغيرة

   • noun phrase, not a full sentence by itself
   • adjective agrees in definiteness
   • means the small pedal

So if you put ال on صغيرة, you change the structure and the meaning.

No.
الدواسة الصغيرة means the small pedal, not The pedal is small.

That phrase is just a noun phrase. It names something, but it does not make a complete statement.

To make a full sentence meaning The pedal is small, Arabic uses:

• الدواسة صغيرة

This distinction between attributive adjective and predicate adjective is one of the most useful things to learn early.

In fully vocalized, formal Arabic, the sentence would typically be:

الدَّوَّاسَةُ صَغِيرَةٌ

That gives:

• الدواسةُ = nominative subject/topic
• صغيرةٌ = nominative predicate

In everyday writing, these short final vowels are usually omitted, so you normally see:

الدواسة صغيرة

Learners should know the endings exist, but it is also normal not to see them written.

Because د is a sun letter.

When ال comes before a sun letter, the l sound assimilates to the next consonant. So:

• underlying form: al-dawāsa
• actual pronunciation: ad-dawāsa

That is why you hear a doubled d sound.

This happens with letters like:

• ت، ث، د، ذ، ر، ز، س، ش، ص، ض، ط، ظ، ل، ن

But with moon letters, the l is pronounced normally.

For this word, yes, it is treated as feminine.
And in many cases, a noun ending in ـة is feminine.

However, as a general rule, ـة is a strong clue, not an absolute rule for every single Arabic noun. Arabic gender is partly predictable and partly lexical, so some nouns just have to be learned with their gender.

For this sentence, the important thing is:

• الدواسة is feminine
• therefore صغيرة must also be feminine

الدواسة صغيرة is the normal, straightforward order for this kind of sentence in MSA.

It consists of:

• الدواسة = the topic / subject
• صغيرة = the predicate

Arabic can sometimes vary word order for style or emphasis, but for learners, الدواسة صغيرة is the standard pattern to remember for X is Y in the present tense.

It shows a very common Arabic pattern:

definite noun + indefinite adjective/noun
to mean
The [noun] is [description].

Examples:

• البيت كبير = The house is big
• البنت ذكية = The girl is smart
• الدواسة صغيرة = The pedal is small

This is one of the most important sentence patterns in Arabic, especially because it works without a present-tense is.