Hi Snn
I think most grammarians prefer the possessive form for the subject of a gerund when the subject is a personal pronoun:
To spy on someone means to watch them secretly, without their knowing....without them knowing is very common but considered wrong by some who think
knowing is a noun. You cannot say:
them car, you have to say
their car, because
car is a noun.
However, some consider a gerund neither a noun nor a verb but a little bit of both, and accept both
their knowing and
them knowing.
If a gerund were a noun, it could take adjectival attiributes because an
adjective can be placed before
nouns. We can say:
an old car
good advice
merry old England
However, very few will consider the following correct English:
Correct speaking French is easy.
Quick learning a foreign language is impossible.
I'm keen on quick learning tennis.If a gerund is a noun, they should be regarded as perfect English. I don't know a single English noun that can't take an adjectival attribute.
Also,
the is possible before
all nouns in certain circumstances. Therefore, if a
gerund were a noun, the following would be correct English:
The speaking foreign languages you described is very interesting.Cheers
CB