You spell it like this: surprise
The correct spelling is "surprise" (an unexpected event).
Yes, "negotiable" is spelled correctly.
You have spelled 'still' correctly.
Yes, engineer is spelled correctly in your question.
You don't. It is spelled "surprise" with no hypens.
Flattest is spelled correctly. The others are spelled: silliest, biggest and sweetest.
Yes, surprisingly is spelled with an S. Surprisingly is how you spell it. You spelled it correctly.
You've spelled it correctly.
In English, "surprise" is spelled properly while "suprise" is not.
Convenience (easy access or availability) is correctly spelled.
Yes, "foreign" is spelled correctly.
Yes, "volunteer" is spelled correctly.