It's kindergartner, not kindergartener.
Yes, "kindergartner" is spelled correctly.
Yes, "negotiable" is spelled correctly.
The current culture has adopted the word 'kindergartner' without the extra E you would use in 'Kindergarten'. Webster's dictionary supports this, while the Free Dictionary says you can use either interchangeably.
You have spelled 'still' correctly.
Yes, engineer is spelled correctly in your question.
Yes, surprisingly is spelled with an S. Surprisingly is how you spell it. You spelled it correctly.
You've spelled it correctly.
Convenience (easy access or availability) is correctly spelled.
Correctly: How did Elise spell? She spelled correctly.
it is correctly spelled iPod.
You spelled it correctly: pumpkin.
You've spelled it correctly.
You've spelled it correctly.