In addition,
gal is an alternative pronunciation for
girl. Back in the 1920s, all the way up until now, but not as prolific in usage, the word
gals was and still is a term of endearment, used by both women and men to refer to adult women.
Today though, given the focus on "language as power", the word
gals is not as common as it was back then because
gals refers to young females, or females who, because of their age, are not taken seriously.
In Asia, being referred to as a
young girl, especially if age is an issue, can be taken as a compliment, but in North American, where being young of age is equated with lack of experience, being called
gal can be taken as an insult. And there's also the diminutive, or endearment part to consider as well. Endearment terms, as you probably already know, tend not to be used in business. Such terms are more common among friend or at home.
As an endearment term,
gals is still in use today, and it's alive and kicking in various dialects, even in idiolects, or a person's preferred usage. A case in point, my sister, who is in her late 20s, uses the term
gals when talking about her adult female friends.
In response to question 2., try,
"This is
my most expensive book."
"This is
the most expensive book I own."
x-mas: