Directly from Latin:
* Loquacious: talkative, chatty
* Elocution: the art of speaking clearly and effectively
* Eloquence: the ability to speak fluently and persuasively
* Soliloquy: a speech delivered by a character alone on stage
English words derived from Latin:
* Dialogue: conversation between two or more people
* Prologue: an introductory speech or section
* Epilogue: a concluding section
* Interlocutor: a person who takes part in a dialogue
* Loquacity: the quality of being talkative
* Circumlocution: the use of many words where fewer would do
* Grandiloquent: using high-flown or bombastic language
* Equivocal: open to more than one interpretation; ambiguous
* Colloquial: used in informal conversation
Other words with related meanings:
* Speak: to utter words
* Talk: to engage in conversation
* Say: to express something verbally
* Converse: to engage in conversation
* Discourse: formal speech or writing
* Address: to speak to or write to someone
* Communicate: to share information or ideas
* Articulate: to express oneself clearly and effectively
* Verbalize: to put thoughts into words
This list isn't exhaustive, but it shows the wide range of words that derive from the Latin root "loq" and its related meanings.