In ordinary discourse we dont encounter all three categories of communication in their pure form. Normally, peoples communication makes use of all sorts of strategies at once. This is also true of arguments, where propositions that are intended to convey information may be phrased in a manner designed to evoke emotion and the entire thing leads to a directive some order that is supposed to follow from accepting the argument in question.
Being able to separate emotional and informational language is a key component of understanding and evaluating an argument. It isnt unusual for the lack of substantive reasons for accepting the truth of a conclusion to be masked by the use of emotional terminology sometimes deliberately, sometimes not.
Deliberate use of emotional language can be seen in many political speeches and commercial advertisements these are carefully constructed to get people to share an emotional reaction to something. In casual conversation, emotional language is likely less deliberate because the expression of emotion is a natural aspect of how we communicate with one another. Almost no one constructs normal arguments in a purely logical form. There is nothing inherently wrong with that, but it complicates the analysis of an argument.
Regardless of the motive, extracting the emotional language to leave just the raw propositions and inferences is important to ensure that you evaluate the right things. Sometimes we have to be careful because even a single word can have a literal meaning which is entirely neutral and fair, but which also carries emotional impact that affects how a person will react.
Consider, for example, the terms bureaucrat and public servant both can be used to describe the same position and both have neutral meanings in their most literal sense. The first, however, will often arouse resentment while the latter sounds far more honorable and positive. Only the term government official can sound truly neutral and lacking in either positive or negative impact (for the time being, at least).
If you want to argue well and do a good job at evaluating the arguments of others, you need to learn how to use language well. The better you are at structuring your thoughts and ideas, the better you will be able to understand them. That, in turn, will enable you to express them in a variety of ways (helping others understand you) as well as allow you to be able to identify flaws which need to be fixed. This is where skills with logic and critical reasoning come in but notice that skills with language come first.