Question: In this sentence: 做乜唔叫埋我? What is the function of 埋?

I understood this sentence to be: "why didn't you call me?" (perhaps to an outing or a party). What is the difference with the sentence "做乜唔叫我"?

Insights please.

Answer: 
1. [V + **埋**] = [**也** + V] = [V + **too**]

Example:

* 叫**埋**佢去 = **也**叫他去 = ask him to go **too**
* 殺**埋**佢隻狗 = **也**殺了他的狗 = kill his dog **too**
* 連你都打**埋** = 連你**也一起**打 = beat even you **too**

2. [V + 埋] = [V + 完] = [finish + V]

Example:

* 執**埋**啲手尾 = 辦**完**那些收尾工作 = **finish** those finishing work
* 計**埋**條數就走 = 計算**完**那筆賬就走 = leave after **finish** calculating the account
* 食**埋**飯先至睇電視 = 吃**完**飯才看電視 = watch T.V. only after **finish** eating dinner

3. [V + 埋] = [V + result particle that means 'conceal'

Example:

* 收**埋**你把手槍 = 收**起**你的手槍 = put away (**and conceal**) your handgun
* 快啲匿**埋** = 快些躲**起來** = hurry up and hide (**and conceal yourself**)

4. [V + 埋] = [V + 貼/ 近] = [V + close]

Example:

* 企**埋啲** = 站**近些** = stand **closer**
* 閂**埋**門打仔 = 關**上**門打兒子 = close the door (**shut**) and beat the son

To answer your question:

> 
> 做乜唔叫**埋**我? = 為什麼不**也一起**叫我? (Why not call me **too**?)
> 
> 
> 

> 
> "做乜唔叫我"? = 為什麼不叫我? (Why not call me?)
> 
> 
>
做乜唔叫我？ => Why didn't (you) notify me?

做乜唔叫**埋**我？ = 做乜唔預我？ = 做乜唔邀請我？ => Why didn't (you) **also** count me **in**? = Why was I kept out? = Why ain't I **also in**vited?

In English, "**also** count (somebody) **in**" means "**in**vite (somebody) **too**", but "count (somebody)" alone has no such clear meaning.

While both questions sounds accusing, 埋 emphasizes that at lease one person is included in an event yet the asker was kept out.