Immatation, Washoe would imitate easily but, the trick was getting her to imitate what they wanted her to actually immitate. Washoe wouldn't sign toothbrush, in the 10th month of training Washoe spontaneously upon entering the bathroom signed 'toothbrush'. Washoe hated having her teeth brushed so she wasn't asking for the gardners to brush her teeth. There seems to be no obvious motive for this except to communicate.
Babbiling, Washoe used a begging gesture, which was not too different from thr ASL signs for give me and come. she also shook her wrist vigorously to indicate hurry. Washoe was reinforced with positive feedback such as clapping at her and smiling and babbiling at her. Funny was acquired this way. First Washoe would babble funny, then the researchers did, then washoe did and so on.
Operant conditioning, Instrumental conditioning was one strategy used with Washoe. Tickiling was the most effective reward as a young chimpanzees have a passion for being tickled. Infact in the early months, Washoe indicated she wanted to be tickled by placing the researchers hands on her ribs. The researchers noticed when she was being tickled she would put her arms over wher she was being tickled so they used this to shape a response for more. this sign was later applied to a variety of relevant situations.