I'd recommend the "Collins COBUILD English Dictionary" (the blue one, 1995
edition). Why? Because all of its examples are taken from real life texts and
conversations, not made up by the dictionary makers! Moreover, possible
grammatical structures associated with a word are clearly listed, which makes
COBUILD superior to Oxford's "Advanced Learner's" and Longman's "Contemporary
English". (But if you insist on using the Oxford and Longman ones, I have
nothing to say...)

COBUILD also lets you know what typically precedes or follows a particular
word when it's used. For example, when you "walk a dog", that means you "take
it out for a walk in order to let it have some exercise." So COBUILD lets you
see the combination "walk" + "a dog".

The "BBC English Dictionary" is pretty much like the COBUILD in terms of
presentation, style of explanation, and method of collecting exemplary
sentences, except that the examples are mostly from BBC's radio programmes.

For the most authoritative dictionary on Earth, consult the 20-volume "Oxford
English Dictionary" (OED). But it is only available in public or university
libraries... BUT, you can buy the CD-ROM version at several thousand HK
dollars!!

Many of you Hongkongers used to buy British dictionaries, right? Pay attention
to certain well-known American dictionaries:

1. The American Heritage Dictionary. This large and thick dictionary contains
much more entries than the Oxford and Longman ones you use. Usage notes, illustrations,
synonyms, word histories and usage notes are provided. But the bad point is that
NOT EVERY WORD OR PHRASE HAS ITS CORRESPONDING EXEMPLARY SENTENCE(S)! This is quite
big a problem. Has CD-ROM version, a thinner COLLEGIATE version, and a pocket-
sized version.

2. Random House Unabridged Dictionary. This is even larger and bulkier than the
AHD and it is $$$$ very expensive! Fairly similar to AHD in terms of the kinds
of information provided. Not too many exemplary sentences either. Has CD-ROM
version.

3. But perhaps the most authoritative one is Webster's Third New International
Dictionary, whose size and number of words/entries are comparable to the
OED (though not as great as it). You don't need to consult that, however, because
it's a bit traditional in presentation and the provision of exemplary sentences.
What is more popular is Webster's Tenth Collegiate Dictionary, which is
based on the giant traditional dictionary. Unfortunately, examples are
fewer compared to the AHD and RHUD.

You should buy a THESAURUS. This is a book which lists the synonyms, antonyms
and other related words of a word. For instance, when you look up 'beautiful'
in a thesaurus, you'll find 'beauteous', 'handsome', 'prepossessing', 'pretty',
'lovely', 'graceful', etc. in a long list. The thesaurus doesn't provide the
definitions of these words and so you have to use a thesaurus together with a
good dictionary. With a thesaurus you can get hold of many words that you can't
think of at the moment, but which might be what you need to express a particular
thought.

Just any thesaurus will do, and there's no need to go for some 'authoritative'
thesauri. I have an inexpensive pocket-sized thesaurus with me:
The New American Roget's College Thesaurus (Published by New American
Library)

I know there're even some English-Chinese thesauri. Check them out.

These books contain notes on possible errors that learners of English may make
when using certain words or structures. For example, wrong uses of tenses,
confusion between words which look alike, uses that are not in line with native
English speakers' habits, and so on. A well-known and very useful usage guide
is:

Michael Swan, "Practical English Usage".

The entries are arranged in alphabetical order, and there are over 600 of
them!! From the correct/acceptable uses of tenses to ways of greeting someone,
from ways of saying numbers in spoken English to the meanings of 'have got',
from the difference between 'continuous' and 'continual' to comparative forms
of adjectives...Incredibly comprehensive. In fact, if you read most of this
book you'll come across many of the topics Mr Lau the local 'English expert'
have talked about in his TV programme, and you'll get the answers Mr Lau gave!

Another very good usage guide is:

Collins COBUILD English Usage.

This is also comprehensive in coverage, but the number of entries seem to be
smaller than that in Michael Swan's book. The COBUILD usage guide is innovative
in that it contains a number of entries not typically found in former usage
guides, e.g. expressions used in telephoning and apologizing, difference between
'shop' and 'store', adverbs and adverbials (in grammar).

A very famous but old usage guide is:

Roger Fowler, "Fowler's Modern English Usage", Oxford U Press. (First published
in 1926!!)

Very thick. Contains entries that have been talked about for many years by Western
writers and language scholars, e.g. a singular or plural verb after a subject,
whether the use of 'like' as in 'I will skip classes today like I did yesterday'
is correct (some argue that 'as' should be used instead of 'like'). But some of
the entries are just too 'Western' -- Hong Kong Chinese will find them useless!
For example, the mispelling of the word 'feldspar', pronunciation of the word
'nugae', modern and original senses of 'ode'...

By the way, I found Fowler's book talks about the need to avoid meaningless
'truisms' (something necessarily true and there's no need for proof), and Mr Lau
talked about this very unusual topic in July 1995. Could it be that he has
'consulted' Fowler's book??

If you want a collection of sample business letters, memos, sales letters, and so
on, and detailed analyses of why the writer of each of these texts writes like
that, take a look at the textbook below:

Duncan Macintosh, "English for Business". Book Marketing Ltd.

It's a book that has undergone many different editions. One of its strengths is
that it gives the meanings of many commercial terms and bureaucratic ways of
saying things indirectly (e.g. "it would be in your interests to do something").
If you'd like grammar exercises alongside instructions on business writing
strategies, this should be the book because it contains many 'Language Exercises'.

Are you interested in knowing more about common English errors Chinese students
make? David Bunton has done a good job in:

David Bunton, "Common English Errors in Hong Kong". Longman.
David Bunton, "Common Written & Spoken English Errors in Hong Kong". Longman.
David Bunton, "Common Social English Errors in Hong Kong". Longman.