الأريكة ثقيلة.

In Modern Standard Arabic, the verb to be is usually not stated in the present tense in sentences like this.

So:

الأريكة ثقيلة
literally looks like the sofa heavy,
but it means the sofa is heavy.

This kind of sentence is called a nominal sentence. In the present tense, Arabic normally leaves out is/am/are.

If you wanted a past or future meaning, Arabic would use a verb such as كان:

• كانت الأريكة ثقيلة = The sofa was heavy

The fully vocalized MSA form is:

الأَرِيكَةُ ثَقِيلَةٌ

More exactly in grammatical form:

• الأريكةُ = subject, nominative
• ثقيلةٌ = predicate, nominative

So the ending vowels are:

• -ُ on الأريكة
• -ٌ on ثقيلة

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

الأريكة ثقيلة

Because الأريكة is a feminine noun, and the adjective must agree with it.

The adjective heavy has:

• masculine: ثقيل
• feminine: ثقيلة

Since أريكة is feminine, Arabic uses the feminine adjective:

• أريكة ثقيلة not
• أريكة ثقيل

A big clue is that أريكة ends in ـة (taa marbuuTa), which often marks feminine nouns.

Because here ثقيلة is not being used as an attributive adjective inside a noun phrase like the heavy sofa. It is the predicate of the sentence: The sofa is heavy.

In Arabic, that distinction matters:

• الأريكة ثقيلة = The sofa is heavy
• الأريكة الثقيلة = the heavy sofa

So in your sentence:

• الأريكة is definite: the sofa
• ثقيلة is indefinite in form because it is the predicate: is heavy

This is a very important Arabic pattern.

You would say:

الأريكة الثقيلة

Here both words are definite:

• الأريكة = the sofa
• الثقيلة = the heavy

That is a noun + adjective phrase, not a complete sentence.

Compare:

• الأريكة ثقيلة = The sofa is heavy
• الأريكة الثقيلة = the heavy sofa

This is one of the most useful contrasts for learners of Arabic.

A careful full pronunciation is:

al-ʾarīkatu thaqīlatun

In pause, which is how people often actually say it, it sounds more like:

al-ʾarīkah thaqīlah

A few pronunciation notes:

• ث in ثقيلة is like th in think
• ق is a deep q sound, not an English k
• the long ī in ثقيلة is held a bit longer: thaqīīla

So ثقيلة is approximately: tha-QII-la

It is an adjective, but in this sentence it is functioning as the predicate.

So grammatically:

• الأريكة = the topic/subject
• ثقيلة = what is being said about it

In English, we say:

• The sofa is heavy

In Arabic, the adjective itself can serve as the predicate in the present tense:

• الأريكة ثقيلة

So yes, ثقيلة is an adjective, but here it is not simply modifying a noun inside a phrase. It is completing the whole sentence.

Because Arabic adjectives normally follow the noun they relate to.

So Arabic says:

• sofa heavy rather than
• heavy sofa

That is true both in:

• noun phrases: الأريكة الثقيلة = the heavy sofa
• simple nominal sentences: الأريكة ثقيلة = The sofa is heavy

For an English speaker, this takes practice, because English adjectives usually come before nouns, but Arabic adjectives usually come after.

In standard Arabic, the normal simple sentence is just:

الأريكة ثقيلة

You usually do not need هي here.

Adding هي can sound:

• emphatic,
• contrastive,
• or less natural in a basic beginner sentence.

So for ordinary MSA, the best version is simply:

الأريكة ثقيلة

A learner should usually treat that as the default pattern.

Yes, أريكة is a standard Modern Standard Arabic word for sofa, couch, or sometimes divan.

However, in everyday spoken Arabic, many dialects often use other words, such as:

• كنبة
• or similar local forms

So:

• أريكة is very good MSA
• but in conversation, the everyday word may vary by country

You would usually say:

الأريكة ليست ثقيلةً

That means The sofa is not heavy.

Here ليست is the feminine singular form used because الأريكة is feminine.

So compare:

• الأريكة ثقيلة = The sofa is heavy
• الأريكة ليست ثقيلة = The sofa is not heavy