Can we use slang in english test?

[Casiopea]

For me that means "In my books those expressions are slang.", because that response can only refer to "It's just colloquial to me.", and not "I don't believe these expressions are slang, are they?", or that response means "Those expression are not in my books.".

So, are you saying, dihen, that the idioms in question are colloquial? They're certainly not colloquial in my books, nor are they slang.

[Mister Micawber]

.
Whether slang, idioms, or colloquialisms, it is not wise to use such phrases in a written essay, which requires more formality than these offer.

A piece of cake -- a simple task
Let someone sleep on it -- let someone think about it carefully
Face the music -- accept the consequences
.
.

[fiona bramble]

My two bits (as a relatively experienced teacher of TOEFL):
Idioms ("face the music" et al.) and phrasal verbs are considered too informal for the writing tasks. You may not lose marks but you will certainly score higher if you don't use idioms and phrasal verbs

[ahfan_85]

My two bits (as a relatively experienced teacher of TOEFL):
Idioms ("face the music" et al.) and phrasal verbs are considered too informal for the writing tasks. You may not lose marks but you will certainly score higher if you don't use idioms and phrasal verbs

I'm grateful for your advice
thanks dude~

[fiona bramble]

I'm grateful for your advice
thanks dude~

dudette