The main metaphor that is used to explain the historical relationship is that of the language family or family tree. - David Crystal

During the later part of the 19th century, it was believed that a sound of change affected the whole of a language simultaneously: one sound system would smoothly develop into the next, and all words which contained a particular sound would be affected in the same way.

I believe that any form of writing exercise is good for you. I also believe that any form of tuition which helps develop your awareness of the different properties, styles, and effects of writing is good for you. It helps you become a better reader, more sensitive to nuance, and a better writer, more sensitive to audience. Texting language is no different from other innovative forms of written expression that have emerged in the past. It is a type of language whose communicative strengths and weaknesses need to be appreciated.

We now know that linguistic change does not operate in such an across-the-board manner. Some speakers introduce the change into their speech before others; some use it more frequently and consistently than others; and some words are affected before others. A more accurate view is to think of a change gradually spreading through the words of a language – a view that is known as a lexical diffusion. At first just a few people use a change sporadically in a few words (commonly occurring words are influenced very quickly); then a large number of words are affected, with the sound gradually being used more consistently; then the majority of the words take up the change.