has been ascertaining

• 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 ascertain (3rd person singular).
  ascertain

  verb (used with object)

  to find out definitely; learn with certainty or assurance; determine.

Related Words

• confirm
• determine
• divine
• double-check
• find out
• verify