Is it correct to write "I could not be able to come " or is there any grammatical mistake ??

Is it correct to write "I could not be able to come " or is there any

1.	Is it correct to write "I could not be able to come " or is there any grammatical mistake ??
Answer» Yah won\'t is more appropriate than could not.... Thanks prakhar ? Don\'t worry u are correct......dont take it seriously...just ignore these things...these may demoralise you...ok....best of luck Anisha..??? If the sentence is absolutely correct then why my teacher scolded me for this..... No it is fully correct But my teacher told me that this sentence is wrong.... She also scolded me for this??? Its fully correct.......?? or else we can use "won\'t" in place of couldnot because it is more polite...i think ?..