"I decided to go on holiday for a week. I think 10 days is too many for me."
Am I correct using 'is' instead of 'are'? Or the only way is to change the phrase to '10-days period is too long for me?'
"I decided to go on holiday for a week. I think 10 days is too many for me."
Am I correct using 'is' instead of 'are'? Or the only way is to change the phrase to '10-days period is too long for me?'
It's not ungrammatical, but it is unnatural.
Consider the more natural "ten days is too long for me".
"Ten days" is conceptualised there as a single abstact entity, hence singular "is".