had been amplifying

• past perfect progressive

  past perfect progressive

  Used to describe an action that was ongoing continuously in the past up until another past event interrupted it.

  of amplify.
  amplify

  verb (used with object)

  to make larger, greater, or stronger; enlarge; extend.

Related Words

• augment
• deepen
• exaggerate
• heighten
• intensify
• magnify
• strengthen