On Monday I caught my usual train and sat in my usual seat, which is the window seat of a three-seater (Sydney trains have three seats on one side of the aisle and two on the other). A few stations along, a woman, clearly from a non-English speaking background, got on and sat in the aisle seat. At the next station a man got on and hovered in the aisle next to her. Train travellers’ etiquette says that the person in the aisle seat either moves to the middle seat, or stands up to let the newcomer past. Some people state where they are going and/or ask where the other is going, so the first off can sit in the aisle seat. The woman said to the man “I go Parramatta”. I didn’t hear what he said, but she stood up to let him past, so presumably he was going further than that. I then fell asleep.
Every language has elements which can be omitted, especially in casual speech; this is called ‘ellipsis’. Native speakers often do this, but are probably unaware that they are doing it, and of exactly which words they are leaving out and why. There are, in fact, very strong, unconscious rules about what can be left out in what contexts. Second language learners or speakers also omit elements of English sentences, but the elements they leave out and the elements native speakers leave out are rarely the same. No native speaker over the age of three ever said, says or ever would say “I go Parramatta”; they would say “I’m going to Parramatta”. They may ask “You goin’ to Parramatta?” or even “Goin’ to Parramatta?”.
The thing is, though, that “I go Parramatta” is a perfectly communicative sentence; it’s got a subject and a verb, and it enabled the woman to say exactly what she needed to say in the context, the man to understand her and respond appropriately, and the two to complete the social transaction to their mutual satisfaction.