have been buttressing

• 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 buttress.
  buttress

  noun

  any external prop or support built to steady a structure by opposing its outward thrusts, especially a projecting support built into or against the outside of a masonry wall.

Related Words

• reinforce
• strengthen
• uphold