Have -- (WT) This helping verb "have" indicates that the verb is the tense indicating an action completed in the past. This is not the tense of the verb here.

not -- The Greek word translated as "not" is the Greek negative used to deny objective facts, not opinions. It means "no," "not," or"no truly." It makes a negative statement of fact. Adding "really" to the sentence captures the same idea. When a negative precedes the verb, it affects the whole clause. When it precedes other words, its force is limited to those words.

I -- The pronoun "I" is used here. Since, as the subject of the sentence, it is part of the verb, its explicit use accentuates who is speaking "I." Saying "I myself" captures this feeling in English.

missing "myself" -- (MW)  The subjective pronoun repeats the information in the verb so it should be repeated in English like "I myself."

chosen - The verb "chosen" means "to pick out" and "to single out." It is in the middle voice, so the sense is "for myself," or "by myself."

you -- The "you" here is the second-person, plural pronoun in the form of an object of the action.

missing "the"  -- (MW) The untranslated word is the Greek definite article, which usually precedes a noun and, without a noun, takes the meaning of "the one." The Greek article is much closer to our demonstrative pronouns ("this," "that," "these," "those"). See this article for more. 

twelve, - -- "Twelve" is the Greek word for the number.

and -- The Greek word translated as "and" is used as the conjunction "and," but it also is used to add emphasis ("also"). In a series, it is can be translated as "not only...but also." After words implying sameness "as."

one -- The Greek word translated as "one " means "one" (as opposed to other numbers), "single," and "one and the same." As in English, it can be used as a pronoun, meaning a single person.

of -- The Greek preposition translated as "of" means "out of" or "from." The word also means "beyond," "on," "in," "since," or "by"based upon its context. However, in Greek, they use the genitive case instead of a preposition for the types of phrases that are translated into English "of" phrases.

you -- The word translated as "your" is a plural, second-person pronoun in the genitive case. This pronoun follows the noun so "of yours."

is -- The verb "is" here is the common form of "to be" in Greek. It means to have a certain characteristic or remain in a certain condition. It also equates terms or assigns characteristics. With the genitive object, the sense is "belongs to."

a -- There is no indefinite article in Greek, but when a word doesn't have a definite article, the indefinite article can be added in English translation.

devil? -- The term translated as "devil" is another adjective, that means "to slander." Introduced by an article ("the") it becomes a noun and means "the slanderer" and "the backbiter" in Greek. Christ uses it to describe someone who degrades other people primarily by lying about them. See this article.