Which is the oldest language of the world, which is still spoken?

Tamil is the oldest language of the world which is still spoken. It is a part of the Dravidian languages It is mainly spoken in the Southern part of India and in Sri Lanka. This language has its own script . Although origin of Tamil is unknown, but is known that it developed much before first century BC when a piece on grammar, namely Tolkappiyam was written in it. In fact, this piece illustrates that the language is much older as the grammar of Tamil was well developed at that time.