Translation Gone Wrong

The other day at work I learned an interesting lesson with languages. You see I can speak and understand portuguese, however my spanish is another story. Here is an example of what  I mean:

Child #1: Como se dice "Free Play" in Espanol?

Me: I don't know let me think (obviously said in spanish)

Child #2: Free Play of course (said sarcastically)

In my head I'm thinking, I know the word for play and free why not give it a try.

Me: Free Play es Juegar Gratis

Child # 2 &3: Haaaaaa....thats not right (as they die of laughter)

So I ask a co-worker of mine who is hispanic what the translation would be since I've already gone wrong. I tell her what I said and she smiled and chuckled slightly. 

Co-worker: Juegar Libre

Child #1: Ay Ok..gracias

Me: Oh that's right, "Free"has more than one translation, of course that was the better option. Lesson learned and noted.