Yep, as Marne said every child with asd is different and will present in his/her own way.
The spectrum is huge and some children are low-functioning, some are high-fonctioning , some are somewhere in the middle, some have co-mordid conditions,... and that is a simplified view of ASD.
Anyway, my DS (who has HFA) at age 3, had less than 50 words, was not linking words, used to request by pulling us by the hand to what he wanted. He didn't follow instructions and his understanding of language was very low too. He made lots of repetitive noises, humming or skrietching,... He didn't try to interact with other children at nursery, but was just starting to play by himself alongside them (parralel-play).
His play was (still is but not as much) very concrete and sensory seeking, had an obvious lack of imagination when playing, only played (for hours on end every day) with his cars and trains, lined them up, and rolled them back and forth often closely at eye level.
Overly sensitive to noises, temperature, lights, textures and foods. Had lots of little rituals that where emerging bit by bit.
Didn't like anyone new coming into our house and had huge tantrums.
I could go on and on... 
but i'll stop now.