+0
I don't know when to put an article before " sterling " . My question is , why shouldn't I put an " a " before " ..done sterling service " in the 3rd sentece . Look at the following sentences :

1 . You've done a sterling job .

2 . Everyone has made a sterling effort .

3 . This old television has done sterling service but it doesn't work very well anymore .

sterling ( adjective ) = of a very high standard , admirable .
+0
This has nothing to do with 'sterling', of course, but with the nature of the noun. 'Job' is countable and singular; 'effort' is here used as a countable singular'; and 'service' is here used as a noncount noun.
Comments  
Teachers: We supply a list of EFL job vacancies
we can not generally count an " effort ' . So , does that mean these two sentences are both right :

1 . Everyone has made sterling effort ( using effort as an uncountable noun ) and

2 . Everyone has made a sterling effort ( using effort as a countable noun ) .

The same thing appllies for the last sentence :

1 . The old television has done a sterling service and

2 . The old television has done sterling service .

The logic being that if I can consider " effort " as countable , so should I be able to do so when it comes to " service " .
'Effort' and 'service' can equally be countable or uncountable, Nayeem-- but it depends on the use and the context as to which may be appropriate.

In the first set we have people making a described kind of effort (a sterling effort), so the countable noun is called for.

In the second set, televisions do not 'do a service'; they 'serve'. Hence, the uncountable 'sterling service' is appropriate.

It may well be that the choice of countable/uncountable for nouns-- and many of them easily assume both forms-- is very much context- and collocation-specific.
That's exactly what I was thinking . Thank you .
Site Hint: Check out our list of pronunciation videos.