If one were to take the 25,000 word Oxford Pocket English Dictionary and take away the redundancies of our rich language and eliminate the words that can be made by putting together simpler words, we find that 90% of the concepts in that dictionary can be achieved with 850 words. The shortened list makes simpler the effort to learn spelling and pronunciation irregularities. The rules of usage are identical to full English so that the practitioner communicates in perfectly good, but simple, English.
We call this simplified language Basic English, the developer is Charles K. Ogden, and was released in 1930 with the book: Basic English: A General Introduction with Rules and Grammar. He founded the Orthological Institute to develop the tools for teaching Basic English. His most famous associate, I.A. Richards, led the effort in the Orient, which uses the techniques to this day.