Correct

当 vs 做

/ dāng vs zuò /
Strokes

Formula

1
当当 (AA)
2
做做 (AA)

Definition

当 and 做 both are Verb, which means [to become; to be].

当 and 做 both have multiple meanings, here only the meaning of "to become or to be" is analyzed.

Example

当 and 做, both words can take a noun expressing the professional title or status as the object.
1) The object of 当 and 做, both verb is a noun that indicates a person including gods, ghosts, etc.

2) It is noteworthy that such a noun represents a status, along with its duty.
1
dāng
  
(
zuò
  
)
le
lǎoshī
老师
  

He became a teacher.

2
èrshí
二十
suì
jiù
dāng
  
(
zuò
  
)
le
jīng
经理
  

She became an manager at 20.

3
Zhè
háizi
孩子
cóngxiǎo
从小
jiù
xiǎng
dāng
  
(
zuò
  
)
gōngchéngshī
工程师
  

The child dreamed to be an engineer since his early time.

There are a few exceptions, one can say 当兵 but not 做兵.
1) But in phrases 当(做)一名小兵 (to be a soldier), 当(做)了将军 (to be general), 当(做)元帅 (to be a marshal), either can be used.

2) When taking the complement 上, 当 is mostly used.
4
毕业
hòu
dāng
shàng
le
tuīxiāoyuán
推销员
  

He worked as a salesman after his graduation.

5
Píng
de
néng
能力
  
,
dāng
shàng
lǐngdǎo
领导
  

He cannot be a leader according to his ability.

With other complements, 当 and 做, either can be used with little difference.
6
dāng
  
(
zuò
  
)
le
liǎng
nián
jīng
经理
  

He worked as a manager for two years.

7
Zhège
这个
guān
yǒudiǎnr  
有点儿
dāng
  
(
zuò
  
)
gòu
le
  
.

He is a bit bored of being an official.

When 当 means "to play the part of or to hold the post of", 做 cannot take its place.
8
Zài
zhège
这个
zhōng
剧中
  
,
dāng
xīnniáng
新娘子
  

She stared the bride in the play.

当 and 做, both words can be reduplicated.
当当 (AA) 做做 (AA)
9
lái
dāngdāng
当当
  
(
zuòzuò
做做
  
)
zhège
这个
zhǎng
科长
  
!

If you were the section chief!

When 当 means "to be used as", it is very close to 做 in the same meaning.
10
Zhè
piān
xiǎoshuō
小说
可以
dāng
  
(
zuò
  
)
wén
语文
jiàocái
教材
  

The novel can be used as language teaching material.

当 can take an object which indicates a person, while 做 cannot.
11
Biè
dāng
rén
客人
  

Don't treat me as a guest.

12
méi
dāng
wàirén
外人
  

I don't take you as a non-family.

做 cannot mean "to be regarded as", while 当 can.
13
Zhè
diǎnr  
点儿
xiǎodōng
小东西
  
,
jiù
dāng
niànpǐn
纪念品
shōuxià
收下
  
!

Take the small item as a souvenir, please!