هيكل الدراجة قوي.

In Arabic, the verb to be is usually omitted in the present tense.

So:

• هيكل الدراجة قوي
• literally: the bicycle frame strong
• naturally: The bicycle frame is strong

This is a very normal Arabic sentence pattern, called a nominal sentence.

If you wanted the past tense, you would use a verb such as كان:

• كان هيكل الدراجة قويًا = The bicycle frame was strong

هيكل means frame, structure, or sometimes skeleton, depending on context.

In this sentence, because it is followed by الدراجة (the bicycle), it means:

• هيكل الدراجة = the bicycle frame

So here هيكل is best understood as frame.

This is because هيكل الدراجة is an iḍāfa construction, often called a genitive construct or possessive construction.

In Arabic, when two nouns are joined like this:

• هيكل الدراجة

it means:

• the frame of the bicycle
• or the bicycle’s frame

In an iḍāfa:

1. the first noun usually does not take الـ
2. the second noun can make the whole phrase definite

So even though هيكل has no الـ, the whole phrase is definite because الدراجة is definite.

Because Arabic expresses possession differently from English.

English often says:

• the bicycle frame
• the bicycle’s frame

Arabic uses the order:

• frame + of the bicycle
• هيكل الدراجة

So the thing being possessed comes first (هيكل), and the possessor comes second (الدراجة).

الدراجة has الـ, so it means the bicycle.

Because it is the second word in an iḍāfa, it makes the whole phrase definite:

• هيكل الدراجة = the bicycle frame

Compare:

• هيكل دراجة = a bicycle frame / the frame of a bicycle
• هيكل الدراجة = the bicycle frame

So definiteness in the second noun is very important here.

Because Arabic normally puts the predicate after the subject in this kind of sentence.

Here:

• هيكل الدراجة = the subject
• قوي = the predicate (strong)

So the structure is:

• [subject] + [predicate]
• هيكل الدراجة + قوي

This is the normal way to say The bicycle frame is strong.

Also, Arabic adjectives normally come after the nouns they describe, so this word order feels natural to Arabic learners very quickly.

Because قوي here is the predicate, not part of the noun phrase.

• هيكل الدراجة قوي = The bicycle frame is strong

In this sentence, قوي is telling us something about the subject, so it does not need الـ.

If you said:

• هيكل الدراجة القوي

that would usually mean:

• the strong bicycle frame

That is a noun phrase, not a complete sentence.

So the difference is:

• هيكل الدراجة قوي = a full sentence: The bicycle frame is strong
• هيكل الدراجة القوي = a phrase: the strong bicycle frame

Yes. قوي agrees with هيكل.

Since هيكل is:

• masculine
• singular

the adjective/predicate is also:

• masculine singular → قوي

If the noun were feminine singular, you would usually use:

• قوية

For example:

• الدراجة قوية = The bicycle is strong

So agreement matters here.

In fully vowelled Modern Standard Arabic, it would be:

• هَيْكَلُ الدَّرَّاجَةِ قَوِيٌّ

These endings show the grammar:

• هيكلُ: nominative, because it is the subject
• الدراجةِ: genitive, because it is the second noun in an iḍāfa
• قويٌّ: nominative, because it is the predicate

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

• هيكل الدراجة قوي

A careful pronunciation is roughly:

• haykalu d-darrājati qawiyyun

Without case endings, learners often say something like:

• haykal ad-darrāja qawiyy

One useful point: in الدراجة, the د is a sun letter, so الـ is pronounced as part of the d sound:

• not al-darrāja
• but ad-darrāja (or d-darrāja in connected speech)

So the l sound of الـ is not pronounced clearly here.

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

So semantically it means an adjective:

• strong

But grammatically in the sentence:

• هيكل الدراجة قوي

it is the khabar (predicate), telling us information about the subject.

This is why it behaves differently from an attributive adjective inside a noun phrase.

Not as written.

Because الدراجة is definite, هيكل الدراجة is also definite, so the sentence means:

• The bicycle frame is strong

If you wanted a more indefinite idea like a bicycle frame, you would change the noun phrase, for example:

• هيكلُ دراجةٍ = a bicycle frame / the frame of a bicycle

So the written definiteness matters a lot.