Ballpoint pen or pen
Ballpoint pen = bolígrafo
Pen = bolígrafo o pluma
Is that it?. Thank you for your answers.
12 Answers
I think that the only difference between a cheap plastic pen and a ballpoint pen is that the cheaper one is disposable and the more expensive, ballpoint, has a refillable cartridge inside.
An interesting fact --
As native English speakers we often misunderstand the word "pin" for "pen." When someone says "Do you have a pen?" we often respond with "Do you want a pin or a pen?" I would then say "I want a pen to write with" or "I need a pin for this shirt."
The pronunciation is so close that even natives have to clarify what they are saying!
I think that they mean the same thing. I only see/hear the word "ballpoint pen" when I read a package and it's describing what type of pen is enclosed. Otherwise, everyone just says "pen."

"Ballpoint pen" and "pen" are for "bolígrafo". The difference is the type of material.
And "fountain pen" should be for "pluma". Is that it?
In the United States, this is one of the most common pens. If you ask for "una pluma" or "un boli" you will get one of these.

Both the Mexicans I knew in LA and the people I talk to in Ecuador use pluma for any kind of pen. Usually it's a ballpoint, but they use the same word for nylon point pens. I haven't used a fountain pen since high school and have never had a chance to hear someone refer to one in Spanish, nor have I heard anyone say bolígrafo, although I have seen the word in print.
A ball-point pen is more often called a "Biro" in England after the Humgarian who invented it. A pen (one with liquid ink) is called a Fountain Pen.
It seems like you're not the only one with this question. You might find this useful http://www.spanishdict.com/answers/121684/pluma-or-boligrafo-for-pen
Take care
Pen is used to mean any writing instrument that uses ink - ballpoint pen, fountain pen, nylon point pen, etc. You write with either a pen or a pencil. You can also write with a marker, which is short for marking pen, but generally only for large writing.
As far as differentiating between the English words pin and pen, it's very common for people from the Southeast in the U.S. to use the phrase, "ink pen".
Unless you ask spefically for a fountain pen, when you ask for a pen you will receive a ballpoint or felt tip pen.
And this is a fountain pen (una pluma) in Spain:

And I suppose that the ballpoint pen is the one that says Marianne with a fillable cartridge inside.
This is a pen (o bolígrafo) in Spain.
