Verily -- The word translated as "verily" is the Hebrew word that means "truly" or "certainly," but it sounds like the Greek word with the same meaning. In Greek, the word also means "to reap."

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

say -- The word translated as "I tell" is the most common word that means "to say," and "to speak," but it also means "to teach," which seems to be the way Christ uses it more frequently. It also has many ancillary meanings such as "to count" ("to number" or like we might say, "to recount" a story) or "to choose for yourself." Christ usually uses this word to refer to his own speaking or teaching.

unto -- This word "unto" comes from the dative case of the following word that requires the addition of a preposition in English, but the translator must decide which preposition to use: a "to" as an indirect object.

you,  -- The Greek pronoun "you" here is plural and in the form of an indirect object, "to you," "for you," etc. 

This  - -- "This" is translated from a Greek word that means "this," "that," "the nearer."

generation  - The word translated as "generation" means "race," "family," and "generation." Jesus uses this term frequently to describe his critics, but that criticism seems more aim at a certain type of person, or, more narrowly, a certain group among his own people, than it is his generation as we used the term. It is the word from which we get the scientific "genus."

shall -- (CW)This helping verb "shall" does not indicate the future tense, but that the following verb describes a possibility, the subjunctive voice. A "might" or "should" in English is more appropriate, but is assumed in an "if/when/whoever/except" clause. Helping verbs are not needed in Greek since the main verb carries this information in its form.

not -- (CW)The "not" here is both of the Greek negatives used together. Greek has two negatives, one objective, one subjective. The use of both together is more extreme, like saying "you cannot really think" or, more simple, "never."

pass, -- The word "pass " is from a verb that means "go by," "pass by," "outstrip" (in speed), "pass away," "outwit," "past events" (in time), "disregard," and "pass without heading." The form is not the future tense, as translated, but in a form that means something is possible. This idea is emphasized by a word that appears in some good Greek sources, but which is not translated in the KJV.

till -- The word translated as "until" means "until" but it also means "in order that."

missing "when"  -- (MW) The untranslated word  "if might" indicates more of an expectation of something happening than "if" alone. This is often how we use the word "when."

all -- The word translated as "all" is from the Greek adjective meaning "all," "the whole," "every," and similar ideas.

these -- The "these" is from a pronoun that can mean "this" or "that," the nearer or the further depending on usage.

things  -- This "things"  is from the plural, neutral form of the previous adjective. Though the subject  here is plural, the verb is singular because neutral plural verbs are treated as a collective.

be -- (WV) This helping verb "be" seems to indicate that the following verb is passive but it isn't. It is a verb form that indicates the subject is acting on itself.  However, since the verb only indicates a possibility, there should be a "might" here.  Helping or auxiliary verbs are needed to translate the Greek verb forms into English.

fulfilled. -- (CW) The word translated as "fulfilled" means "to become" and "to happen," that is, to enter into a new state. Another Greek word is usually translated as "fulfill" in Greek. It is also not in the future tense, but the form that indicates something that might happen. Since it refers to events, the sense is "happen." The form is that of things acting on themselves, which is captures by our word "happen," which doesn't suggests and outside force.