Introducing English Linguistics

has written several books. 
(ICE-GB W2D-019 068)
Headland 
is buying Multisoft, a software group which makes business
accounting systems designed for the personal computer market. 
(BNC A1S 81)
He 
named like half a dozen viruses
(SBCSAE)
The key test for an object is that it can be made subject of a sentence in
the passive voice:
Several books were written by her.
Multisoft is being bought by Headland.
Half a dozen viruses were named by him.
However, because the acceptability of a passive construction is, as was
demonstrated in the last chapter, very context-dependent, often pas-
sivization of an object yields a sentence of questionable acceptability. For
instance, while similarities between the two kinds of parents in the example
below is a direct object, passivization results in a sentence that is gram-
matical but of questionable acceptability:
We