Re: Vocabulary size

>I hear that a vocabulary of about 3000 words (base forms I assume) is
>adequate for communication in English.

This is completely misleading.  With 3000 words one would not be able
effectively to communicate - though most native British speakers use
far fewer than this in day to day communication.

One needs approximately 100,000 lexical phrases to communicate
effectively and naturally.  However, bear in mind Krashen's
observation that a vocabulary of 100,000 items does not imply either
100,000 fill-in exercises or 100,000 trips to the dictionary.  We have
acquired, rather than formally learned, most of the vast mental
lexicon which we carry prefabricated and ready for use (see "The Power
of Reading" by Stephen Krashen, publ. Libraries Unlimited, Inc.).