Earlier today I started to type a message and I entered:
I can take a couple of hours...
After entering the text, I realized that I intended to express roughly three hours so I highlighted and replaced the word "couple" with "few".
The resulting statement, before further edits, was:
I can take a few of hours...
Being that I am an American and English is my primary language, I paused for a moment to consider this phrasing of the second statement. It is completely wrong and feels awkward but I have no clue why.
To further confound the problem "a few of" is not always improper wording. Consider "I will take a few of them." In this context, "few of" is correct and, simply, "few" is wrong?!
The similarities and nuances of the words "couple" and "few" have been frequently discussed, even here on English.SE. Even after reading a few questions relating to these words on this site, it has always been my working assumption that these words have the same general meaning, except a couple is a relative quantity of two while a few was a relative quantity of three or a few more (pun intended.)
What is the nuance difference between these two words, in light of the above context?