As Adapt It performs the adaptation process, if it does not find an adaptation in the knowledge base, it copies the source text into the Phrase box. You can change this behavior. By doing the following steps:
Open the View menu in the Menu bar.
Clear the Copy Source option.
Adapt It leaves the Phrase box empty when it encounters an unadapted source text location.
To restore normal process, follow the above steps and click the Copy Source option.