Why are ing important

-ing is a suffix used to make one of the inflected forms of English verbs. This verb form is used as a present participle, as a gerund, and sometimes as an independent noun or adjective. The suffix is also found in certain words like morning and ceiling, and in names such as Browning.

in macbeth, banquo, who in real life had willing in the murder of king duncan, is portrayed as a loyal subject of the king himself. many analysts believe that shakespeare had done this in order to king james, who supposedly was a direct descendant of banquo himself.

hope this ! : )

i suggest it is anadiplosis