A dictionary of Confusable Phrases: More Than 10,000 Idioms and Collocations

tea boy • tea man
tea boy —(UK) 
1
. a boy employed to run errands in an office,
etc.: I left school at 
1
7 and I started straight away in a recording
studio, initially as a tea boy then trainee tape operator. 2.
(coll.) a general assistant: Mr. Fenby says he began his career
as a journalist employed as a “tea boy” at Reuters news agency.
Note: 
The expression does not correlate in meaning with the
phrase tea girl—(also: tea lady) a woman employed to make and
serve tea in an office: She started out as a tea girl, then office
junior in a busy credit department.
tea man —
1
. a merchant who deals in tea: The Chinese tea-
men maintain a sort of incredulous nonchalance in the face
of that almost complete capture of the market by the Indian
teas. 2. (also: tea master) a man in charge of serving tea at a
tea-party or other social occasion: In Kamakura for the first
time a tea man did the tea ceremony for me.
tea hostess • tea lady
tea hostess— a woman in charge of serving tea at a tea-party
or other social occasion: Mrs. Bowhill acted as model for the
evening dress. Tea hostesses were Mrs. Kedge and Mrs. Wil-
liams.
tea lady —(also: tea girl) a woman employed to make and
serve tea in an office: Two years ago, it seemed the ubiquitous
tea lady was vanishing beneath a tide of vending machines.
teach an old dog new tricks • teach one’s
 grandmother to suck eggs
teach an old dog new tricks —is used to say that old people
can hardly be expected to learn anything new: This computer
is far too difficult for me. You can’t teach an old dog new tricks.
Note: 
a) The expression does not correlate in meaning with
the phrase teach a pig to play the piano—do futile work at -
tempting to deal with smb. who is absolutely hopeless: Teaching
them democracy? It would be easier to teach a pig to play the
piano.
b) The expression does not correlate in meaning with the phrase