I understand what you are trying to say in your explanation, but your grammar is incorrect. "cause I was learned it before, ..." this could confuse someone that is trying to understand the English language. Technically you should not use Cause in place of Because. The words have two completely different meanings. Cause is a noun and is used to describe the reason for an action, or something that brings a result. Because is a conjunction and is used to describe the reason behind something done. Using 'cause for because is considered slang and is not excepted in formal writing and should not be used verbally when in a professional setting. If you are writing and you are quoting someone that used 'cause in a sentence, you can use the word, just be sure to add an apostrophe before the C, or you can write it as follows [be]cause, include quotation marks around the sentence.