For non-native speakers who learned Indonesian language, if you go to some place in Indonesia and listen to conversations of the natives there, you may realize that you don’t understand many words they say. They tend to talk with shorter words than what you have learned in class. But don’t worry, they will still understand your proper class taught way of speaking and respect you more because you know good grammar. 

So these are several examples that I can think of for now:

1. Verbs beginning with me-, most of the time the word me- can be omitted or replaced with nge-, ng- or ny-. 

Menyapu –> nyapu 

Menyetrika –> nyetrika

Memasak –> masak 

Mencuci –> nyuci

Menipu –> nipu

Membasuh –> ngebasuh / basuh

1. In Java island, and maybe Bali and Lombok, in casual conversation it is more common to replace the suffix –kan with –in.

Memperkenalkan –> ngenalin (k replace with ng)

Menidurkan –> nidurin

Meniupkan –> niupin

Diambilkan –> diambilin 

1. Prefix be- is also sometimes omitted during casual conversation

Begitu –> gitu

Berdamai –> damai

Berlari –> lari

Bergoyang –> goyang

Can anyone think of any more examples?