Just the way you have spelt it in your question: ninety.
It seems like there may be a typo in your question. Did you mean to ask how to spell a different word correctly? If you provide the word you would like assistance with, I can help you spell it correctly.
ninety nine
The word, locally, is spelt correctly in the question.
The word is correctly spelled "background".
Nineteen Hundred and Ninety-five
ninety-one
the ninety-first
ninety-one dollars and ninety-eight cents.
The word form is five hundred ninety-three and ninety-eight hundredths.
Ninety three and five hundredths.
bye
Sardoodledum.
There is no such word as 'deaserd' - did you spell it correctly ?
There is no such English word, did you spell it correctly.
You have spelled it correctly.
You spelled it correctly.
You have spelled it correctly.