[译] 患失语症时患者丧失说话和书写的能力。
[误] On aphasia, the patient loses the ability to speak and write.

[正] In aphasia, the patient loses the ability to speak and write.
[注] 表示“患某种病时”用介词in,不用on。又如:In syphilis, the spirochets enter the body at the point of contact through mucous membranes. 患梅毒时,螺旋体通过粘膜接触侵入人体。