I -- This is from the first-person, singular form of the verb.

am -- This helping verb indicates the present tense of the verb. It is used here to form the present, progressive tense, which doesn't exist in Greek but which can smooth the flow of English sentences.

referring -- (WW) The word translated as "referring " is the most common word that means "to say," "to tell," and "to speak,"  but when used with an objective noun or pronoun, the sense is "say of" or "speak of."

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. 

all: -- The word translated as "all" is the Greek adjective meaning "all," "the whole," "every," and similar ideas. When it is used as a noun, we would say "everything." As an adverb, it means "in every way," "on every side," and "altogether."

of  -- (CW) The Greek word translated as "of" means "around" when referring to a place, but in referring to a subject, it means "about," "concerning," "on account of," and "in regard to." This is the way Jesus usually uses it. It is not the word form usually translated as "of."

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

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."

know -- The word translated as "know" means primarily "to see" and is used to mean "know' as we use the word "see" to mean "know" in English. It is the past perfect tense so "have seen" but it is translated as the present tense of "know."  What someone "has seen" is what they "know" in the present.

those -- The Greek word translated as "whom" in the singular means "anyone," "someone,"  "something," and "anything." The same forms are used both for the masculine or feminine so "anyone" works best for a person. In the plural, it means "everyone," "some," "they," and "those." Jesus often uses it to start a question so it means "who," "what," or even "why."

I -- This is from the first-person, singular form of the verb.

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.

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."

But -- (CW) The Greek word translated as "but" denotes an exception or simple opposition. It is used to emphasize the contrast between things like we use "instead," "but instead,"or "rather." It is not the common word usually translated as "but." It is the Greek word "other" like we use "otherwise." Jesus often uses this conjunction to connect a negative clause, "not this," with a positive one, "instead this."

this is to -- (CW) The word translated as "this it to" is a conjunction that starts a subordinate clause  "that," "when," "in order that" or "because."

fulfill -- (WM, WV) "Fulfill" is a verb that means "to fill," "to fulfill," and "to fill full." This is a passive, subjective verb, "may be fulfilled."

this -- The word translated as "this" is the Greek definite article, without a noun, it has the sense of "the one." The Greek article is much closer to our demonstrative pronouns ("this," "that," "these," "those") than the English "the." See this article for more. 

passage of (IP) There is nothing that can be translated as "passage of " in the Greek source.

Scripture: (CW, WF) "Scripture" is a noun that means "writing", "the art of writing," and "that which is written," so, the "writing." It doesn't have the specific sense of religious writing that "scriptures" does. It might also be worth noting that the Greek word translated as "scriptures" literally means "a drawing." For the Greeks, both drawings and words created a "picture" or a man-made, artificial representation of reality. This is not a possessive form (of Scripture), but the subject of the verb "may be fulfilled."

He-- (CW) The word translated as "he" is the Greek definite article, without a noun, it has the sense of "the one." The Greek article is much closer to our demonstrative pronouns ("this," "that," "these," "those") than the English "the." See this article for more. 

who -- (IW) There is nothing that can be translated as "who " in the Greek source. It was added because the next verb was translated as active rather than as a participle.

shared - (WW) The Greek verb translated as "eating" means "to gnaw," "to nibble," and "munch," but it usually refers to herbivorous animals. It specifically means to eat vegetables or fruit. This is the least common and most humorous word Jesus uses for eating. It is different than the Greek word used in the OT Psalms quote which was the most common word with the simple sense of just "eating."

missing "the/this"  -- (MW) The untranslated word is the Greek definite article,"the," 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.

bread -- The word translated as "bread" means "small loaf or cake of bread." It is more like a slice of bread today. It describes a thin 1/2 inch thick round or an oblong loaf of wheat bread, meant to be torn into pieces and not cut. It was closer to a flour tortilla or a piece of pan than a loaf of bread. "Bread" is one of Christ's most basic symbols, representing temporary physical nourishment as contrasted with permanent spiritual nourishment.

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

turned   - (WW) - The word translated as "lift up" means "lift up," "exalt," "magnify," "set on," "raise," "stir up," "excite," "urge on," and "persuade." This is also a different verb in the OT quote, but that verb was more confusing, meaning primarily to "make great," and so to "exalt," or "magnify." That word has a secondary meaning of "aggravating" a crime.  The Hebrew verb is almost always used in a positive sense.

missing "of his"  -- (MW) The untranslated word "of his" is the Greek word commonly translated as third-person pronouns in English. This pronoun follows the noun so "of his."

missing "this"  -- (MW) The untranslated word is the Greek definite article,"the," 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.

missing "heel"  -- (MW) The untranslated Greek noun that means "heel", "the under part of the heel", "hoof", "heel [of a shoe]", "foot," or a lower part of anything." Jesus only uses this word here, which is common when he is quoting the OT.

missing "of his"  -- (MW) The untranslated word "of his" is the Greek word commonly translated as third-person pronouns in English. This pronoun follows the noun so "of his."

against -- The word translated as "against" means "on," "over," "upon," "against," "before," "after," "during," "by" "in the case of."

me. - "Me" is the regular first-person pronoun in Greek as the object of the verb or preposition. As the object of a preposition, an accusative object indicates movement towards something or a position reached as a result of that movement.