الترجمة مهمة.

In Arabic, the verb to be is usually not stated in the present tense.

So Arabic says:

• الترجمة مهمة
• literally: the translation important
• natural English: The translation is important or Translation is important

This is called a nominal sentence. The first noun is the topic, and the second part gives information about it.

If you wanted past or future, Arabic would use a verb, such as كانت or ستكون.

Because الترجمة is a feminine noun, and Arabic adjectives must agree with the noun they describe or the noun they refer to.

So:

• الترجمة = a feminine noun
• مهمة = feminine form of important

The masculine form is:

• مهم

Compare:

• الكتاب مهم = The book is important
• الترجمة مهمة = The translation is important

Because الترجمة is the subject/topic of the sentence and is definite here, while مهمة is the predicate adjective.

In sentences like this, Arabic commonly uses:

• definite noun + indefinite adjective/predicate

So:

• الترجمة = the translation / translation in a general sense
• مهمة = important

If you said المهمة, that would mean the important one or the important [feminine thing], which is a different structure.

So الترجمة مهمة is the normal way to say:

• The translation is important
• or more generally, Translation is important

It can mean either, depending on context.

Arabic often uses the definite article الـ in places where English might use:

• the translation
• or translation in a general sense

So this sentence could mean:

• The translation is important — if you are talking about a specific translation
• Translation is important — if you mean translation as an activity or field

Context tells you which meaning is intended.

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

So grammatically:

• الترجمة = the subject/topic
• مهمة = the predicate, describing the subject

In English, we also use adjectives after to be:

• The translation is important

Arabic just leaves out the present-tense is.

In fully vocalized MSA, it would usually be:

• التَّرْجَمَةُ مُهِمَّةٌ

Why?

• التَّرْجَمَةُ takes ـُ because it is the subject/topic of the sentence
• مُهِمَّةٌ takes ـٌ because it is an indefinite predicate in the nominative

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

• الترجمة مهمة

The letter ة is called taa marbuuTa.

Its pronunciation depends on position:

• At the end of a pause, it is usually pronounced like -a
  
  • الترجمة ≈ at-tarjama
  • مهمة ≈ muhimma
• In full grammatical reading, when endings are pronounced, it sounds like t
  • التَّرْجَمَةُ
  • مُهِمَّةٌ

So learners often hear both effects depending on how carefully the sentence is read.

Because ت is a sun letter.

When الـ comes before a sun letter, the l sound is assimilated to the next consonant.

So:

• written: الترجمة
• pronounced: at-tarjama (or with full vowels, at-tarjamatu)

The ل is still written, but it is not pronounced as l here.

The basic forms are:

• تَرْجَمَة = translation
• مُهِمّ = important (masculine)
• مُهِمَّة = important (feminine)

So in the sentence:

• الترجمة = the translation
• مهمة = important in feminine form

Yes, but it means something different.

• الترجمة مهمة = The translation is important / Translation is important
• ترجمة مهمة = an important translation

Why the difference?

Because ترجمة مهمة is a noun + adjective phrase, not a full sentence. It describes a translation.

So:

• الترجمة مهمة = complete sentence
• ترجمة مهمة = noun phrase

It comes from the root ت ر ج م.

This root is connected with translating and interpreting. From it you get words such as:

• ترجمة = translation
• يترجم = he translates
• مترجم = translator

Knowing the root can help you recognize related vocabulary later.