The meanings of these three words are very similar, and all relate to creations of the imagination. But there are some nuances. If it’s in a negative context—not being factual for the purpose of being deceptive—use “fictitious”. If you are discussing literature, use “fictional”. “Fictive” is less common than the other two, and is often used in the phrase “fictive kinship” which is a relationship based not on familial ties but on a close relationship. (e.g. when you call your mother’s best friend Aunt Sue)
A comparative adjective (worse) is used when you are comparing two things. A superlative adjective is used when you are comparing three or more things. Unless you are comparing sausage, and then you may need to use “wurst”.
A couple important points to remember:
You probably wouldn’t stalk shelves.
A laughing stalk is probably some kind of character in an animated feature. A laughingstock is a person, or thing, that is being ridiculed or mocked.
“What is the rational?” does not mean the same thing as “What is the rationale?”
To wander about a place is not the same as to wonder about a place. If you have never been to a place, you may have wondered about it, but you have not wandered about it.
If you see a sign for “Tutoring”, someone is offering to help you with your academic pursuits. If you see a sign for “Tutoring”, that could possibly be an offer for historical reenactments or house renovations.
If you are weary of a situation, you are tired of it. You want to be done with it. If you are wary of a situation, you are paying close attention.
You exacerbate a situation, and you exasperate a person–potentially because you exacerbated a situation.
It is better for an author to create a backlist than to create a backlog.