Instruction or Instructions?

[rexcali]

which of these is correct when you use it on a test?
Instruction or Instructions?

[Barb_D]

Hi, and welcome to Using English.

Usually, we'd talk about the instructions we give on a test.

[rexcali]

Thanks a lot. I read from a grammar book that Instruction is never used with an s. (be it singular or plural).

[Koronas]

It can be singular or plural, dependent on context.

"The sergeant gave the recruit an instruction, which he had to obey."
"The sergeant gave his instructions to the recruit."

One word which is NEVER plural in English is "information".

[Barb_D]

There is also the uncountable form: I need more instruction on how to use my new smart phone.

[cubezero3]

Hello, everyone.

I am confused here.

I need more instruction on how to use my new smart phone.

I need more instructions on how to use my new smart phone.

Since either of the sentence is correct here. Why haven't people chosen one of the forms and used them all the time? Surely that would have saved a lot of time.

Maybe there is a cultural differece here? I've long heard the English speaking peoples like their diversities. And probably it's because of this, there're so many different forms being in the currency, which by and large have the same meaning and similar usage.

Many thanks

Richard