TASK DEFINITION: Given the Question and Answer pair, detect whether the answer is acceptable or not. Denote acceptable answer as "yes", otherwise denote as "no". An acceptable answer is consistent with the context in question, detailed, long, and uses general knowledge of English. Answers that are not definite and suggest a variety of options are not acceptable answers.
PROBLEM: Question: Is there a word which has this definition: usage of vulgar or abusive words too often especially while chatting or talking to someone or while giving a speech. What do you call a person who uses abusive words too often without needing to. 
Answer: Two excellent choices exist. The first can be used as either an adjective or noun, in slightly different forms: foulmouth, adj. and n. B. n. A foul-mouthed person. ["foulmouth, adj. and n.". OED Online. June 2016. Oxford University Press. (accessed August 21, 2016).] The adjective 'foulmouth' is obsolete in that form. Instead, the current version is 'foulmouthed': foul-mouthed, adj. Of persons and their utterances: Using obscene, profane, or scurrilous language. ["foul-mouthed, adj.". OED Online. June 2016. Oxford University Press. (accessed August 21, 2016).] The second choice is not so commonly used, and is only found as a noun. However, there's no mistaking its meaning: muck-spout n. regional and slang a person who uses obscene or foul language. ["muck, n.1". OED Online. June 2016. Oxford University Press. (accessed August 21, 2016).].

SOLUTION: yes

PROBLEM: Question: I am looking for a word or phrase which can be used in the sentence: It is a rather old, but _________________ technology. The word or phrase should address a technology that is totally investigated, researched in detail, and thoroughly optimised, so there is nothing more to find out or improve. 
Answer: There is a common acronym for this, used in computing and engineering, which is COTS - "commercial off-the-shelf" - i.e. you can buy it ready made without having to do any research to invent it yourself, and without needing to understand every detail of how it works. It is rather old, but COTS technology.

SOLUTION: no

PROBLEM: Question: What is the shortest comprehensive sentence in English? 
Answer: No. Also Q: Which is the fifth letter of the alphabet? A: E.

SOLUTION:
no