We sometimes get lost while reading because it is hard for us to understand some new words. One of the first things to do is to look around THIS word and see if the context can help us understand the field; one second thing is to check what part of speech we are trying to understand -is it a verb or a noun? an adjective?....
In this part of the process it is good to have a clear idea of some concepts like PREFIXES AND SUFFIXES and their meanings.
It is interesting to note that a prefix will never change the part of speech. For example, if we add the prefix "im" to the adjective "possible", the new word we will form will also be another adjective, "impossible" in this case. Whereas a suffix will always change the word into another part of speech. If we add the suffix "ity" to the adjective "possible", the word coming out will become a noun, "impossibility".
After you have looked up at the Prefixes and Suffixes explanations try and do some exercises.