Related Clues:

• Action part of a sentence
• Trick or treat, e.g
• "Walk" or "crawl" or "sink" or "swim"
• It may be helping or linking
• Stop, drop or roll
• 'Sit,' 'stay,' or 'shake,' e.g
• Word of doing
• Word like ''be'' or ''go''
• To be or not to be, for one, is part of speech
• Word classification
• Do or die, for example, for Rose leaving Observer
• ''Make'' or ''break''
• Part of speech so in need of alteration, finally
• A part of speech
• Best or worst? As such, it doesn't make much difference