These are the so called 'phrasal verbs'. You can find them in all good dictionaries and they are are used instead of one single, specific and exact verb in order to express the same meaning. Phrasal verbs are also the more colloquial English, used by all English speakers around the world on a daily basis. And last but not least, learning them could get easier if you have by your side a good English to English dictionary with examples such as: go away=leave or fade away=to become very weak, sick/ill and die or in this case an example we usually use is 'after some time memories fade away'= they become less strong. Generally, you will find it easier to understand and thus learn them if you get a solid explanation of when and how they are used.

"Away" is an adverbial particle meaning "from here to somewhere else." In the case of "go," it's like changing "ir" to "irse." You can also say "run" (correr) and "run away" (irse corriendo). In the case of "fade," the use of "away" indicates that the fading is complete, to the point where the object has disappeared entirely.

"Away" has the meaning of not here, or sometimes, not there. So for example, a sound that 'fades away' gets softer and leaves here. "Take away" means to take something and move it to "not there". For example, "My dog was chewing on my shoes, so I took them away," meaning I took them AND they are not in his location anymore. Other combinations, like the phrase "right away" (meaning as soon as possible) are just idiomatic and should be remembered. Unfortunately, I don't think there's a trick for these. Hope that helps!