Using a few instead of few in a sentence changes a sentence's meaning. Whereas "a few" implies a small number of some that is greater than two, "few" implies only a small number. Other words, like "very" or "quite," may also come before "a few" or "few" and further change sentence meaning. Examples can be found below.
Comparison chart
 | A Few | Few |
|---|---|---|
| Meaning | "A few" means "some" or "a handful". | "Few" means "virtually none" or "almost zero". |
| Connotation | "A few" connotes "not an overwhelmingly large number, but not an insignificantly small number either." | "Few" without the preceding "a" connotes "an insignificantly small number" |
Examples of "Few" and "A Few" in a Sentence
- "A few of us plan to visit our friend in the hospital later today." [Some of us plan to visit our friend in the hospital later today.]
- "Few of us would rather be sick with a cold than go to work." [Only a small number of us would rather be sick with a cold than go to work.]
- "You can take a few of the brochures." [You can take some of the brochures.]
- "She left the last few pieces of candy for her friend." [She left only a small number of candies for her friend.]
Effects of Modifiers
Other words can further modify the meaning of "a few" and "few." For example, "quite a few" changes the meaning of "a few" from some to many: "Quite a few people attended the party." In other words, many people attended the party.
Similarly, "very few" emphasizes just how few things or people are being discussed: "She used very few buttons on her art project." In other words, she didn't use many buttons at all.
Etymology
The word "few," which can be used as a noun, pronoun, and adjective, comes from Old English. It specifically means seldom or little and is able to function as both a describing word when it is an adjective and a word that can be described when it is a noun.
Affect 
It's 
Data 
Loose 
Envy 
Their
Comments: A Few vs Few