Depends on how good your with languages and the time you spend studying. However, I have heard that in some Spanish schools they teach you enough Spanish to carry on a limited conversation in 6 weeks. You do have to study 8 hrs a day and you live with a family who only speaks Spanish, thus making you speak Spanish from the time you wake up till you go to bed.
Keep in mind that Spanish varies throughout Latin America and that it is best if your teacher is Colombian, as and idioms take different meanings in different countries and sometimes they may be offensive for a particular country.

It would be up to you and how fast you can pick-up a new language

Spanish can be tricky so it depends on your ability to learn new languages, your own practice and study. One thing that works great is by listening to songs in spanish. You just download the music and lyrics and that helps A LOT with vocabulary and giving you some speaking flow…it really works. Buy a good english/spanish dictinary and learn a new word every day. That will give you good foundations for when you come to Colombia. I recommend songs by Shakira (colombian) .

hi! i took one year of spanish in highschool and then i went abroad for 6 months in chile(i stayed with a native family). i learnt a lot of spanish…but i took another 6 months of spanish once i came back from chile and i still practice my spanish A LOT on MSN messenger. the truth is that i learnt a lot of basic spanish words and lots of native slang, however, i am NOT fluent — i can communicate and understand a lot, but still have a lot to learn.
if you want to become fluent, i’d give it … maybe a year or two more living in a foreign country or … five years or so more in the united states, however, it is DEFINETELY POSSIBLE TO LEARN ENOUGH TO COMMUNICATE AND MAKE FRIENDS AND HOLD NORMAL CONVERSATIONS.
how long are you going to stay in columbia for?
hope your success truely depends on you and not only how easily you learn, but how strongly you want to learn.
good luck
xao=D

If you are like me, it would take much longer, but don’t fret… I am not the norm! Staying with the family will help you understand much better and faster. Most of my Spanish I learned in only 5 weeks. It’s not much, but I had some girls living with me. We HAD to communicate. I haven’t learned much outside of that. My brother-in-law lived here for only a few months, and learned fluent English in that time! You will do fine, don’t worry. Take the lessons to get a head start, but it’s not that easy without having someone nearby to keep you at it.

it going to take long take the lesson today or want ever you have time

10 years

all depends in your ability to learn another language, and how much interest you put on, I study engllish by my self, and learnt in a few months, but after 7 years I’m still learning.