Related Clues:

• Grammar concern
• Like a guitar string
• Like a trampoline's surface
• Nervously impatient
• Far from laid-back
• Form of a verb
• Hardly loose
• Unable to relax
• Inclined to fidget
• Stretched to the max
• Like violin strings
• Having no slack
• Grammatical time setter
• Temporal language element
• Pacing, perhaps