Lexicology is the part of linguistics which studies words. This may include their nature and function as symbols, their meaning, the relationship of their meaning to epistemology in general, and the rules of their composition from smaller elements (morphemes such as the English -ed marker for past or un- for negation; and phonemes as basic sound units). Lexicology also involves relations between words, which may involve semantics (for example, love vs. affection), derivation (for example, fathom vs. unfathomably), usage and sociolinguistic distinctions (for example, flesh vs. meat), and any other issues involved in analyzing the whole lexicon of a language.