Vocabulary and Grammar are both key elements of language. I am more interested in vocabulary.

I think that technology and the ease of cultural sharing has changed both vocabulary and grammar.

We have books, movies, television, radio.... from around the world. There is more mixing of "English language culture". Addtion of new words and retiring of old words happens much more quickly. Also word already in use take on new meanings. Langauage is a living thing. Growth and change are happening more quickly than ever before.

Texting has made language at once more abbreviated and more verbose. Words and phrases are shortened but there seems to be more words exchanged.

This of course makes it more important for us to keep ourselves updated with both technology and how the langauage is changing

This makes more for the teen to learn. He wants to be in with his peers and perhaps on top of his or her academic work as well. It is a challenge for them as students and us as teachers.