يظن صديقي العلاج مهما.

A simple breakdown is:

• يظن = he thinks / he believes
• صديقي = my friend
• العلاج = the treatment
• مهما here = important in the accusative form مهمًّا

So the structure is:

• verb: يظن
• subject: صديقي
• first object: العلاج
• second object / complement: مهمًّا

With verbs like ظنّ, Arabic often uses two objects, so the idea is literally something like:

• My friend considers the treatment important.

Because in Arabic, the verb to be is usually not expressed in the present tense.

So:

• العلاج مهم = The treatment is important

There is no separate present-tense is.

The same idea stays true after يظن:

• يظن صديقي العلاج مهمًّا = My friend thinks the treatment is important

So Arabic does not need a word corresponding to English is here.

Because Arabic commonly allows verb–subject order.

So this sentence begins with the verb:

• يظن صديقي... = thinks my friend...

This is a very normal Arabic pattern.

You could also say:

• صديقي يظن العلاج مهمًّا

That is also correct, but it gives a slightly different flow or emphasis. Both mean the same thing here.

يظن is the 3rd person masculine singular imperfect form of ظنّ.

That means it matches a subject like:

• he
• or a masculine singular noun such as صديقي = my friend

So:

• يظن صديقي = my friend thinks

If the subject were I, you would say:

• أظن = I think

If it were you masculine singular:

• تظن = you think

Because ظنّ is one of the verbs that takes two objects.

Compare:

1. Basic sentence:

   • العلاج مهم = The treatment is important

2. After ظنّ:

   • يظن صديقي العلاج مهمًّا = My friend thinks the treatment is important

After ظنّ, both:

• العلاج
• مهمًّا

are in the accusative.

So this is not just a plain noun sentence anymore. The verb ظنّ changes the grammar of what follows it.

Yes. In fully vocalized Arabic, the sentence would be:

• يَظُنُّ صَديقِي العِلاجَ مُهِمًّا

The important endings are:

• العلاجَ with fatḥa because it is the first object
• مهمًّا with fatḥa/tanwīn fatḥ because it is the second object or complement

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

• يظن صديقي العلاج مهما

But grammatically, the full form is العلاجَ مهمًّا.

Because مهمًّا here is not another definite noun. It is the predicate-like complement describing the first object after ظنّ.

So:

• العلاج = the treatment
• مهمًّا = important

In English we also say:

• the treatment is important

We do not say:

• the treatment is the important

So in Arabic, مهمًّا stays indefinite.

Because it describes العلاج, and العلاج is masculine singular.

So the adjective must agree with it in:

• gender
• number

That is why you get:

• العلاج مهمٌّ in a simple sentence
• العلاج مهمًّا after ظنّ

If the noun were feminine, the adjective would also be feminine.

The ـي is the suffix meaning my.

So:

• صديق = friend
• صديقي = my friend

This is called a possessive suffix.

Also, because صديقي is attached to my, its case ending is not shown in the usual way at the end. In a sentence like this, it is still the subject of يظن.

Yes. A very common alternative is:

• يظن صديقي أن العلاج مهم

This also means:

• My friend thinks that the treatment is important

So Arabic gives you two common patterns:

1. ظنّ + two objects

   • يظن صديقي العلاج مهمًّا

2. ظنّ + أن + clause

   • يظن صديقي أن العلاج مهم

Both are correct. The first is a bit more compact and grammatical-tradition-oriented; the second may feel more straightforward to many learners because it resembles thinks that... in English.

Good question, because the spelling without vowels can look identical.

Here, the intended word is:

• مهمًّا = important (accusative)

But without full vowel marks, it may appear as:

• مهما

That same spelling can also represent:

• مَهْمَا = whatever / no matter what

You tell the difference by:

• context
• and, in fully vocalized text, diacritics

In this sentence, the grammar clearly requires an adjective meaning important, so the correct reading is:

• مهمًّا

Yes, it is grammatically valid and understandable in Modern Standard Arabic.

A fully vocalized version would look more clearly natural:

• يَظُنُّ صَديقِي العِلاجَ مُهِمًّا

Many learners may also find this version easier to process:

• يظن صديقي أن العلاج مهم

Both are good MSA. The version with أن may feel more transparent at first if you are coming from English.