Words do grow.

How can the number of words in  language grow?

English is a highly dynamic language, used worldwide by an ever-growing community of speakers. Blog like Basic Educare contribute to this growth, by assisting native and foreign speakers alike to write and use English more frequently, and properly.
What this boils down to is simple: the more people use language, the more that language grows. With the help of the internet, a never-ending cycle of communication is in perpetual motion. And right now, you are a part of it, just by reading this article!

3 WAYS LANGUAGE CAN GROW:

1) SLANG
Most slang terms start out in spoken communication only, and are not considered "proper" enough to be included in formal writing (i.e. business correspondence, school papers, or e-mails to people with whom you aren't familiar).
Over the years, many slang words have progressed from inclusion in spoken English, into proper written English.

2) TECHNOLOGY

As new things are invented, new words are born.
Words like computer, television and radio are only as old as the objects they reference. Concepts like SMS messaging and social-networking sites (i.e. Facebook, Twitter) – are two examples of technological terms that did not exist a few years ago, at least not to the same extent we use them today.
p/s: So learn as you grow to grow more words then. - adz