I help when writing goes astray, then slowly wear myself away.

I come in pairs but hate to stay together I live on your feet but never walk I often go missing but never say goodbye

I sit above the mouth you feed, and help detect what you may need. A rose, a fire, a fresh-baked treat, I sense them all before you eat.

Filled with breath, I grow with ease, pulled by hands or carried by breeze. At parties I gather in colorful crowds, yet one sharp touch can make me loud. Tied with a knot so I do not flee, the higher I drift, the smaller I seem to be.

I am a small round fruit that grows in bunches. I can be purple, green, or red. What am I?