Teacher Discussion Forums

So I was teaching the passive voice the other day and there was an article where they had to circle all of the ocurrances of the passive voice. I'd taught them the formula: to be+past participle. As we were checking one of my students pointed out the occurance of the sentence, "These machines were in use for 15 years." I looked at it and it seemed to be used the same way a passive voice is used, except it doesn't follow the formula.

If I said, "the machines were used for 15 years" then this would follow the formula.

But "in use"? What is this exactly? It seems to be a set verb structure that can't be put in the passive because it seems to be MADE to express the passive.

Anyway, confused. No one knows. Can't find an answer in any books. I told the student I'd get back to her with some kind of response. I'm not sure she really cares, now it's just an obsession of mine.

HELP

one of my students pointed out the occurance of the sentence, "These machines were in use for 15 years."

......

If I said, "the machines were used for 15 years" then this would follow the formula.

Careful! Note that you've "lost" the 'in' there!

Compare:
1a) We used these machines for 15 years
1b) These machines were used for 15 years (by whoever, wherever etc)
2a) These machines were in use for 15 years (by whoever*, wherever etc)
2b) *These machines were in used for 15 years

That is, the reason it doesn't follow the formula for the passive is because it isn't a passive structure, but a prepositional phrase! (Compare: The machines were in Russia for 15 years before we bought them to the UK). That's not to say that it isn't similar to the passive in meaning, however.

Note there is also the verb phrase 'to use sthg in/sthg BE used in' (differing word order to 'be in use').

This parser is useful:
http://www.eslcafe.com/forums/teacher/v ... php?t=2611

*Note that the appearance of 'by...' doesn't make 'in use for' any more passive; in fact, my intuition tells me that 'at' or 'in' would be much more likely than 'by': ?/*'These machines were in use for 15 years by Russia/IBM etc', versus 'These machines were used by Russia for 15 years'.