Choose the right grammatical form in each gap to complete the text

Word [forming|form|formation|formed]is the process of changing a word to get another word. [Basic|Basically|Basical|Basics], we use a root, add or change a part and get a new word. There are four major options to form a new word: using suffixes or prefixes, conversion, and making compounds.

Lots of words are made using prefixes. Prefixes are some letters which are added to the beginning of a word. It's useful to know the[mean|meanings|meaningful|meaningless]of some prefixes. For example, we [knowledge|know|knowing|unknown]that such prefixes like un-, il-, im-,ir-, etc. usually give the opposite meaning. The prefix pre- means "before", the prefix post- means "after", etc. This knowledge can help to boost a person's vocabulary [drama|dramatical|dramaticaly|dramatically].