had been modifying

• 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 modify.
  modify

  verb (used with object)

  to change somewhat the form or qualities of; alter partially; amend.

Related Words

• adapt
• adjust
• correct
• customize
• repair
• reshape
• revise
• rework
• tweak
• vary