[病号1] He can plays the guitar.
　　[诊断] 情态动词can(should、must等)+行为动词原形。句中行为动词不因人称、时间状语而变化。
　　[处方] He can play the guitar.
　　
　　[病号2] They would like buying some things for the party.
　　[诊断] would like 表示“想要”。would like +事物,表示“想要某物”;would like +to+行为动词原形,表示“想要做某事”。
　　[处方] They would like to buy some things for the party.
　　
　　[病号3] Here are some apple juice for you.
　　[诊断] some 意为“一些”,但其后跟随的“apple juice”是不可数名词,所以are 要改成is。
　　[处方] Here is some apple juice for you.
　　
　　[病号4] The girl in the red is my good friend.
　　[诊断] in +颜色,意为“穿着某种颜色的衣服”,中间不加定冠词the。
　　[处方] The girl in red is my good friend.
　　
　　[病号5] Nancy is sitting near she’s tent.
　　[诊断] she’s=she is ,意为“她是……”,要表示“她的”应该用物主代词 her。
　　[处方] Nancy is sitting near her tent.