بعد از امضا، خواهرم گفت که میخواهد دیوار اتاقش را آبی کند.

بعد از means after. The word امضا literally means signature or signing, depending on context.

So بعد از امضا can be understood as:

• after the signing
• after signing
• after the signature

In Persian, it is very common to use a noun like this where English might prefer an -ing form. So instead of saying something shaped like after signing, Persian often says after the signing with a noun.

خواهرم means my sister. The -م at the end is a possessive ending meaning my.

So:

• خواهر = sister
• خواهرم = my sister

This is extremely common in Persian. Instead of using a separate word for my, Persian often attaches it directly to the noun.

For comparison:

• خواهرم = my sister
• خواهرت = your sister
• خواهرش = his/her sister

You can also say خواهر من, but خواهرم is more natural and more common in ordinary speech.

Persian often leaves out subject pronouns when they are already clear from context. This is called pro-drop.

In this sentence:

• خواهرم گفت already tells you who did the speaking: my sister said
• later, میخواهد is understood to refer to the same person unless something else is introduced

So Persian does not need to repeat او (she/he) the way English often does.

Here که works like that in English.

So:

• گفت که... = said that...

In Persian, که is very commonly used to introduce a subordinate clause after verbs like:

• گفتن = to say
• فکر کردن = to think
• دیدن = to see
• شنیدن = to hear

Just like English, it can sometimes be omitted in informal language, but using که is very normal and clear.

Yes—modern standard spelling usually writes it as می‌خواهد with a half-space after می.

So the standard form is:

• می‌خواهد

You may still see:

• میخواهد

They mean the same thing. The difference is mainly typographical/spelling convention.

Grammatically:

• می‌ is the present/imperfective prefix
• خواهد comes from خواستن = to want

So می‌خواهد means he/she wants.

Because after می‌خواهد (wants), Persian normally uses the subjunctive form of the following verb.

So:

• می‌خواهد ... کند = she wants to do/make ...
• not می‌خواهد ... می‌کند

This is a very important pattern:

• می‌خواهد برود = she wants to go
• می‌خواهد بخواند = she wants to read
• می‌خواهد آبی کند = she wants to make it blue

The verb کند is the subjunctive form of کردن.

This is a very common Persian pattern:

[object] + را + [adjective/noun] + کردن

It means: to make [object] [adjective/noun]

So here:

• دیوار اتاقش را = the wall of her room
• آبی کند = make blue

Together:

• دیوار اتاقش را آبی کند = make the wall of her room blue

Other examples of the same pattern:

• اتاق را تمیز کرد = he made the room clean / he cleaned the room
• موهایش را کوتاه کرد = she made her hair short / she cut her hair short
• خانه را خراب کردند = they made the house ruined / they destroyed the house

را marks the specific direct object.

In this sentence, the thing being affected is:

• دیوار اتاقش = the wall of her room

Because it is a definite/specific object, it takes را:

• دیوار اتاقش را

This is very typical in Persian:

• کتاب را خواندم = I read the book
• در را بستم = I closed the door
• دیوار را آبی کرد = she made the wall blue

So in this sentence, را shows that the wall of her room is the object being changed.

اتاقش means his room or her room.

Breakdown:

• اتاق = room
• -ش = his/her/its

Persian does not distinguish grammatical gender in this possessive ending, so -ش can mean:

• his
• her
• its

In this sentence, since the person being talked about is خواهرم (my sister), we understand اتاقش as her room.

So:

• دیوار اتاقش = the wall of her room

Persian usually expresses X of Y by putting the nouns next to each other, often with an ezafe relationship.

Here:

• دیوار اتاقش = the wall of her room

More literally:

• wall room-her

This noun-linking structure is one of the most basic patterns in Persian.

Examples:

• درِ خانه = the door of the house
• رنگِ ماشین = the color of the car
• دوستِ من = my friend

In normal writing, short vowels including the ezafe are often not written, so you see دیوار اتاقش, but it is understood as divâr-e otâqash in pronunciation.

آبی is the normal adjective meaning blue.

So:

• آبی کند = make blue / paint blue

Persian color adjectives often work very simply in this kind of construction:

• قرمز کند = make red
• سفید کند = make white
• سبز کند = make green

You could sometimes see other expressions in different contexts, but آبی is perfectly natural here.

It is mostly neutral standard Persian.

A few notes:

• می‌خواهد is standard
• گفت که is normal and natural
• دیوار اتاقش را آبی کند is a standard grammatical structure

In everyday conversation, someone might say something very similar. So this is a good sentence to learn from because it is not unusually literary or overly formal.

A natural pronunciation would be approximately:

ba'd az emzâ, khâharam goft ke mikhâd divâr-e otâqash râ âbi kone

A few useful notes:

• بعد از often sounds like ba'd az
• خواهرم = khâharam
• می‌خواهد in colloquial pronunciation often becomes something like mikhâd
• کند in colloquial speech often sounds like kone

So the written sentence is standard, but in everyday speech the pronunciation may be a bit more relaxed.