The differences lie in context and the connotations associated with those contexts. Many words mean one thing in one situation and something different in another. Additionally, to express the same sentiment in different contexts may require different words.
This phenomenon is not unique to the English language because it is a feature of language itself. For example, the Spanish language has two ways to say excuse me. Perdón (which literally translates pardon) means excuse me in the context of interrupting a conversation or introducing something or someone new into a social situation. However, to say excuse me in the context of physically moving among other people, the expression is con permiso (which literally translates with permission).
The English language has similar features. Take the word few, for instance. As used in the example sentence in the cropped graphic above, few carries a negative connotation. To say “their report recommends few options” suggests that other plausible options exist but were excluded from the report. It suggests the writer knows more than what the report provides.
Now notice the difference made by adding the word a before few.
Both usages do not preclude the possibility that more options exist. Suggesting something may have been excluded or declaring what has been included could both mean that the report might have contained more than it did. But the change in focus creates a change in context which communicates two different messages.
And there is nothing “wrong” with either message, so long as the writer intends to communicate that message for his or her specific audience. Audience is the main consideration here. And more effective writers always make that and other key considerations.
So make sure you do too. There’s less than a few considerations about few, but more effective writers communicate more effectively because they remember those key considerations in their writing. And more effective writing tends to make more effective presentations, which in turn tend to represent you and your brands more positively to your audience.