Sentence:  Yet , in spite of this , intensive study of the taped interviews by teams of psychotherapists and linguists laid bare the surprising fact that , in the first five minutes of an initial interview , the patient often reveals as many as a dozen times just what 's wrong with him ; to spot these giveaways the therapist must <WSD>know</WSD> either intuitively or scientifically how to listen . 
Meaning of the word marked with <WSD> tags:  know how to do or perform something