تحترق الورقة قرب خطر الحريق.

تحترق is the 3rd-person feminine singular imperfect form of احترق, which means to burn / catch fire.

It matches الورقة because ورقة is a feminine singular noun in Arabic. That is why the verb begins with تـ.

So:

• الورقة = the paper
• تحترق = it burns / it is burning

Fully vowelled, it is تَحْتَرِقُ.

Arabic imperfect verbs can cover several meanings depending on context:

• burns
• is burning
• sometimes will burn

In this sentence, the most natural reading is burns or is burning.

Modern Standard Arabic does not always separate simple present and present continuous the way English does.

Here it is understood as active/intransitive, meaning the paper burns or the paper catches fire.

That is different from a passive meaning like the paper is burned by something else.

A useful contrast:

• تحترق الورقة = the paper burns / catches fire
• تُحرَق الورقة = the paper is burned

So in your sentence, the paper itself is undergoing the burning, not being described with an English-style passive.

Because verb + subject word order is very common in Modern Standard Arabic.

So:

• تحترق الورقة = normal, neutral written style
• الورقة تحترق = also correct, but gives a bit more emphasis to the paper

Both are grammatical. Arabic often allows more than one word order, with small differences in emphasis.

قرب means near or close to.

In this sentence, it works like a preposition-like adverbial noun, so Arabic does not need another word such as to or at before the next noun phrase.

So:

• قرب خطر الحريق = near the fire danger / near the fire hazard

In fully vowelled Arabic, this would be قُرْبَ here.

It is an idafa construction, also called a genitive construction.

Literally, it means:

• خطر = danger
• الحريق = the fire / the blaze

Together:

• خطر الحريق = danger of the fire
• often more naturally in English: fire danger or fire hazard

A key point about idafa:

• the first noun usually does not take ال
• the second noun can make the whole phrase definite if it is definite

So خطر الحريق is normal Arabic structure.

الحريق and النار are related, but they are not exactly the same in tone.

• النار = fire, flame
• الحريق = a fire, blaze, conflagration; often more formal

In safety language and warnings, الحريق is very common. That is why خطر الحريق sounds like formal wording such as fire danger or fire hazard.

So this choice feels more official or technical than النار.

It is grammatically understandable, but by itself it sounds a little unusual.

Whether it feels natural depends on what you mean:

• If you mean near the actual fire, Arabic would more naturally say قرب الحريق or قرب النار.
• If you mean near a fire-danger area or warning zone, something like قرب منطقة خطر الحريق may be clearer.
• If you mean because of the danger of fire, then بسبب خطر الحريق would be better.

So the sentence can be parsed, but in isolation it feels a bit stiff or context-dependent.

A full reading would be:

تَحْتَرِقُ الوَرَقَةُ قُرْبَ خَطَرِ الحَرِيقِ

Breakdown:

• تَحْتَرِقُ = verb
• الوَرَقَةُ = subject, so it is nominative
• قُرْبَ = adverbial expression of place, so it is typically accusative
• خَطَرِ = genitive because it follows قرب in an idafa-like structure
• الحَرِيقِ = genitive because it is the second part of خطر الحريق

In normal unvowelled Arabic writing, these endings are usually not shown.