Read pages 14–17 of Plag (2003) on inflection vs. derivation.
Choose two of the following affixes (or any other interesting example), and using all the criteria discussed in Plag, show whether the affixes count as (more) inflectional or (more) derivational.
Suggestions as to what affixes you can choose:
a) re- (rewrite), or -ess (hostess), or -ment (resentment), or its equivalent in your mother tongue;
b) a diminutive suffix;
c) an adverb forming suffix (Czech -e/-ě or -y; English -ly; Spanish -mente etc.);
d) Czech nej- (lepší 'better‘ → nejlepší 'best‘).
So, for example, you have to choose two, so you can choose e.g. the English re- and the Czech nej-.