المراقبة مهمة هنا.

Because Arabic often uses a nominal sentence in the present tense and leaves out the verb to be.

So:

• المراقبة مهمة هنا
• literally: the monitoring important here
• natural English: Monitoring is important here / Surveillance is important here

In the present tense, Arabic usually does not say a separate word for is.
If you wanted the past, then a verb would appear, for example:

• كانت المراقبة مهمة هنا = Monitoring was important here

المراقبة is a noun, not a finite verb here.

More specifically, it is a verbal noun (often called a maṣdar) related to the idea of monitoring, observing, surveillance.

It comes from the verb:

• راقب = to monitor / observe / watch

So المراقبة means something like:

• monitoring
• observation
• surveillance

depending on context.

الـ is the Arabic definite article, usually translated as the.

So مراقبة = monitoring / surveillance
and المراقبة = the monitoring / the surveillance

But in Arabic, a definite noun can sometimes be used where English would still sound more natural with a general meaning, especially with abstract nouns or verbal nouns. So this sentence can still be translated naturally as:

• Monitoring is important here

not only:

• The monitoring is important here

The exact nuance depends on context.

Because المراقبة is a feminine singular noun, and the predicate adjective agrees with it.

• المراقبة = feminine singular
• مهمة = feminine singular form of important

The masculine form would be:

• مهم

The feminine form is:

• مهمة

So Arabic agreement requires:

• المراقبة مهمة
• not المراقبة مهم

Here it is functioning as an adjective used as the predicate of the sentence.

It describes المراقبة:

• المراقبة = the subject/topic
• مهمة = what is being said about it: important

So the structure is basically:

• المراقبة = monitoring
• مهمة = important
• هنا = here

Together: Monitoring is important here.

A learner may also notice that مهمة can be a noun in other contexts, meaning task or mission. But in this sentence, it clearly means important.

Because Arabic word order is flexible, and this placement is very natural.

In this sentence:

• المراقبة = subject/topic
• مهمة = predicate
• هنا = adverb of place (here)

So the sentence flows as:

• Monitoring is important here

Putting هنا at the end is normal and neutral.

Arabic could reorder things for emphasis, but this version is straightforward and common.

In fully vowelled Arabic, it would typically be:

• المراقبةُ مهمةٌ هنا

Breaking that down:

• المراقبةُ = subject of the nominal sentence, so it is in the nominative
• مهمةٌ = predicate, also nominative
• هنا = an indeclinable adverb of place, so it does not take a normal case ending

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

• المراقبة مهمة هنا

A careful pronunciation would be approximately:

• al-murāqabatu muhimmatun hunā

If you pause naturally at the end and do not pronounce full case endings, it will sound more like:

• al-murāqaba muhimma hunā

A few pronunciation notes:

• ق in المراقبة is a deeper q sound, not an English k
• ة at the end of المراقبة and مهمة is usually pronounced like -a when stopping
• هنا is hunā, with a long final ā

The final ة is called tāʾ marbūṭa.

When you stop at the word, it is usually pronounced like:

• -a or -ah

So:

• المراقبة sounds like al-murāqaba
• مهمة sounds like muhimma

But when the word is followed in a grammatical context where endings are pronounced, the t sound can appear:

• المراقبةُ
• مهمةٌ

and in connected grammatical speech, that final letter is historically a t sound.

For beginners, the main thing to remember is: when pausing, it usually sounds like -a.

Yes. المراقبة can cover several related ideas, including:

• monitoring
• observation
• watching
• surveillance

The best translation depends on context.

For example:

• in a classroom or quality-control setting, monitoring may be best
• in a security context, surveillance may be better

So the Arabic word is broad enough to allow different English translations.

In sentences like this, the predicate is often indefinite in Arabic.

So:

• المراقبة مهمة
• literally: The monitoring [is] important

This is a very common pattern:

• الجو جميل = The weather is جميل / The weather is beautiful
• الكتاب مفيد = The book is useful

If you said المهمة here, it would change the meaning and would no longer simply mean important. In fact, المهمة is more likely to be understood as the task / the mission, because مهمة can also be a noun.

So in this sentence, the indefinite مهمة is exactly what you want.