i actually don't know what grammatical name you would give to that "when", but it's definitely a legitimate construction. all you have to know is that "when" can modify time periods.vikram4689 wrote:What is the function of when in below sentence from OG. when only acts as conjunction or adverb. if 'when' acts as conjunction, simultaneous actions are described but that is not the case here. Only case remains that 'when' acts a adverb but which verb it is modifying. to me it seems to modify at nights or on weekends
As the cost of wireless service has steadily dropped over the last year and as mobile phones have become increasingly common, many people are finding that they can avoid toll charges on their home phones by using their mobile phones to make long-distance calls at night or on weekends, when many wireless companies provide unlimited airtime for a small monthly fee
if you just remember the way in which "when" is used in this example -- and can recognize that kind of usage in future instances -- then you're all set.
here's another example:
On Saturday afternoon, when I was visiting my grandparents, an earthquake struck.
again, i don't know the formal grammar analysis here. it's clear that "when" is modifying (on) Saturday afternoon, which is a time period, so you're all good here.
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more generally, you should avoid an over-emphasis on naming things -- because the whole skill set of naming things is completely irrelevant to this exam. all you need is functional knowledge; i.e., you just have to be able to USE these constructions. it's immaterial whether you can name them.
as an analogy:
do you know what all the parts of a window are called?
probably not.
does this mean you can't open, close, or fix a window?
of course not.
same goes for sentences.
the only things you really have to be able to name are the super-basic building blocks (noun, verb, clause, etc.) as far as these sorts of unique or eccentric examples are concerned, there's no need to waste your time on terminology; just learn how they do work and how they don't work.

















