Huh

Because that’s totally how words, suffixes and conjugation works.

Hmm.... funny that "Sci enti fic" does mean "Know that it is fiction" but "Scienti fic" means "Scientific fiction" and "Sci entific" means "Know the originator" and "Scientific" means......."Scientific" because we already use the Latin word in everyday English.

Lucky for us there are other languages than English and Latin