ترس الدراجة صغير.

In Arabic, the present-tense to be is usually not expressed in simple sentences like this.

So:

• ترس الدراجة صغير
• literally: gear the-bicycle small
• natural English: The bicycle gear is small

Arabic simply places the subject and the description next to each other. This is called a nominal sentence.

If you wanted was, Arabic would usually use a verb such as كان:

• كان ترس الدراجة صغيرًا = The bicycle gear was small

This is a nominal sentence in Arabic.

It has two main parts:

• ترس الدراجة = the subject
• صغير = the predicate / description

More technically:

• ترس الدراجة is the مبتدأ in meaning
• صغير is the خبر

So the structure is:

• [noun phrase] + [description]
• The bicycle gear + small

That is a very common Arabic pattern.

Because ترس الدراجة is an iḍāfa construction, often called a possessive construction.

An iḍāfa links two nouns:

• first noun: the thing possessed or specified
• second noun: the owner/specifier

So:

• ترس = gear
• الدراجة = the bicycle

Together:

• ترس الدراجة = the gear of the bicycle
• more naturally: the bicycle gear

In an iḍāfa:

1. the first noun does not take ال
2. the second noun is often definite if the whole phrase is definite
3. the second noun is in the genitive

With full endings, this would be:

• تِرْسُ الدَّرَّاجَةِ صَغِيرٌ

Notice the -i sound on الدراجةِ.

Because in an iḍāfa, the first noun normally does not take ال.

So Arabic says:

• ترس الدراجة

not:

• الترس الدراجة

Even though ترس has no ال, the whole phrase can still be definite because the second noun is definite:

• الدراجة = the bicycle

That makes the whole phrase definite:

• ترس الدراجة = the bicycle gear / the gear of the bicycle

This is a very important Arabic pattern.

Because ترس is a masculine noun.

The adjective or predicate must agree with the noun in gender and number, so Arabic uses:

• ترس ... صغير = The gear is small

If the noun were feminine, you would usually use:

• صغيرة

For example:

• الدراجة صغيرة = The bicycle is small

Here, though, the thing being described is ترس, not الدراجة.

That is why the sentence ends with صغير, not صغيرة.

It is an adjective in meaning, but in this sentence it functions as the predicate of the sentence.

So:

• in vocabulary terms: صغير = small
• in sentence structure: it is the word that tells us something about ترس الدراجة

Compare:

1. ترس الدراجة صغير
   = The bicycle gear is small
   Here صغير is the predicate.

2. ترس الدراجة الصغير
   = the small bicycle gear
   Here الصغير is a regular attributive adjective inside the noun phrase.

That distinction is very useful.

Because it is the predicate of the sentence, not part of the noun phrase.

In Arabic, predicates in simple present-tense nominal sentences are often indefinite:

• البيت كبير = The house is big
• الجو جميل = The weather is nice
• ترس الدراجة صغير = The bicycle gear is small

If you said:

• ترس الدراجة الصغير

that would usually mean:

• the small bicycle gear

So adding ال to صغير changes its role.

A careful fully-vowelled pronunciation is:

• tirsu d-darrājati ṣaghīrun

Word by word:

• تِرْسُ = tirsu
• الدَّرَّاجَةِ = ad-darrājati or more precisely d-darrājati after the article assimilates
• صَغِيرٌ = ṣaghīrun

In normal pause, many case endings are not pronounced, so you may often hear something closer to:

• tirs id-darrāja ṣaghīr

Both careful grammar-based pronunciation and pause pronunciation are useful to learn.

Because د is a sun letter.

With sun letters, the ل of ال is not pronounced separately; instead, the following consonant is doubled.

So:

• الدراجة
• not pronounced al-darrāja
• but roughly ad-darrāja / id-darrāja depending on context and vowels

This is called assimilation of the definite article.

That is why you hear a doubled d sound.

ترس means gear, cog, or sprocket, depending on context.

In a bicycle context, it refers to one of the toothed wheel parts of the mechanism.

So ترس الدراجة could be understood as:

• the bicycle gear
• the bicycle cog
• sometimes the bike sprocket, depending on what part is meant

The exact English word depends on the technical context, but gear is a good general translation for learners.

Yes, in fully vocalized formal Arabic it would typically be:

• تِرْسُ الدَّرَّاجَةِ صَغِيرٌ

The endings show the grammatical roles:

• ترسُ = nominative
• الدراجةِ = genitive, because it is the second term of the iḍāfa
• صغيرٌ = nominative predicate

However, in ordinary unvowelled writing, you usually just see:

• ترس الدراجة صغير

And in speech, especially in pause, those final short vowels are often dropped.

Normally, this sentence is understood as definite:

• ترس الدراجة = the bicycle gear / the gear of the bicycle

That is because الدراجة is definite, and in an iḍāfa this makes the whole phrase definite.

If you wanted something more indefinite like a bicycle gear, you would need a different structure, for example something like:

• ترسٌ لدراجةٍ
• depending on the intended meaning

So the given sentence is not usually read as A bicycle gear is small.

Because Arabic normally places the predicate after the subject in a basic nominal sentence.

So the order is:

• subject first
• description second

That gives:

• ترس الدراجة صغير
• The bicycle gear is small

This is very normal Arabic word order.

English needs is, but Arabic does not in the present tense, so the sentence may look short to an English speaker even though it is complete.