has been heightening

• present perfect progressive

  present perfect progressive

  Used to describe an action that began in the past, has continued continuously, and is still in progress.

  of heighten (3rd person singular).
  heighten

  verb (used with object)

  to increase the height of; make higher.

Related Words

• add to
• boost
• enhance
• improve
• increase
• magnify
• raise
• strengthen