For --  -- (OS) There is nothing in the Greek that can be translated as "for" in the source we use today but it does exist in the source that the KJV translators used.

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." This verse starts with the "amen" phrase, which we discuss in this article.

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

say -- The word translated as "say" is the most common word that means "to say," and "to speak," but it also means "to teach," which seems to be the way Jesus 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."

unto -- This is from the form of the following pronoun, which is an indirect object and requires a preposition in English.

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

That -- The word translated as "that" introduces a statement of fact or cause.

 whosoever-- "Whoever" is from a special construction connecting a pronoun with a conditional particle. Together, they begin a relative, conditional clause that refers to each individual person or thing.

shall -- (CW) This does not indicate the future tense. It indicates that the verb is in the form of possibility. A "might" is more appropriate, but if the verb appears in an "if" statement, the possibility rather than certainty is assumed.

say -- "Say" is from the Greek verb that means "to say" and "to speak" also.  This is a different word than the "say" above.

unto -- This is from the form of the following pronoun, which is an indirect object and requires a preposition in English.

missing "the/this"  -- (MW) The untranslated word is the Greek definite article.  The Greek article is much closer to our demonstrative pronouns ("this", "that", "these", "those"). See this article for more. 

this -- "This" is a demonstrative pronoun that means "this", "here", "the nearer," and "the familiar."  It appears after the following noun.

mountain, -- (MM) The word translated as "mountain" means "mountain" or "hill" but it could also be the word which means "mule." It could also be a third word, spelled just like the Greek word "mountain" means "boundary," "barrier," and "the decision of judges." Both word, "mountain" and "mule" are in the form of an indirect object and the surround definite article and demonstrative pronoun agree with both, even though they are different genders, "mule" being masculine and "mountain" being neutral. The feeling of the word is a stubborn barrier.

Be -- This comes from the passive form of the following verb.

thou -- This comes from the second-person, singular form of the verb.

removed, -- (MM) "Removed" is one of Jesus's favorite "multiple meaning" words. It is a verb that means "to raise up", "elevate", "to bear", "to carry off", "to take and apply to any use," and "to cause to cease." Jesus uses this verb to refer to what will happen to "the son of man," which can apply either to his being raised from the dead or lifted up on the cross. The phrase "pick up" captures both the "raise" and "remove" idea in English.,

and -- The Greek word translated as "and" is used as the conjunction "and", but it also is used to add emphasis ("also").

be -- This comes from the passive form of the following verb.

thou -- This comes from the second-person, singular form of the verb.

cast -- The word translated as "cast" has a number of meanings revolving around "throw" as we do in English with both "throw" and "toss." Jesus often uses this word in the same way we use "dump" in English. In dice, it means "to throw" the dice, but with the sense of being lucky.

into -- The word translated as "unto" means "into" a place, "towards" as a direction, and "up to" limits in time and measure.

the -- The word translated as "the" is the Greek definite article. The Greek article is much closer to our demonstrative pronouns ("this", "that", "these", "those"). See this article for more. 

sea; -- The "sea" is from the Greek word for "sea" and "sea water." Water is Christs symbol for the temporary, physical reality.

and -- The Greek word translated as "and" is used as the conjunction "and", but it also is used to add emphasis ("also").

shall -- (CW) This does not indicate the future tense. It indicates that the verb is in the form of possibility. A "might" is more appropriate.

not -- The negative used here is the Greek negative of a subjective opinion, commands, and requests. The sense is that "you don't want" to do something, not that it isn't done or don't think something that might be true. If it wasn't done or wasn't true, the objective negative of fact would be used.

doubt -- (WW, WV) The verb translated as "doubt" means to "separate" and "divide." Its root is a common word that means "separate" and it is usually translated as "judge" in the Gospels. The form is passive in the form of possibility so "might be divided." This verb is still part of the "if" statement.  This idea of "being divided" creates a play on word with the word translated as "mountain," which also means "barrier" and the "decision of judges." It is not the active voice but the passive.

in -- The word translated as "in" also means "within", "with," or "among."

his-- The word translated as "his" is the Greek word commonly translated as third-person pronouns in English. This word follows the noun so "of his."

missing "the/this"  -- -- (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. 

heart, -- "Heart" is the Greek word that means "heart" both the physical organ and as the seat of emotions, which we discuss in a larger Greek context in this article here. However, this phrase can be read as defining the "heart" and both the "soul" and "the mind".

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 almost always uses this conjunction to connect a negative clause, "not this," with a positive one, "instead this."

shall -- (CW) This does not indicate the future tense. It indicates that the verb is in the form of possibility. A "might" is more appropriate.

believe -- (CW) The Greek word translated as "believe" does not apply to religious belief as much but trusting or relying upon other people, especially their words. Jesus usually uses it in contexts, such as the one here, that apply to trusting words. See this article.

that -- The word translated as "that" introduces a statement of fact or cause.

those -- The word translated as "those" is a demonstrative pronoun ("this" "that"), but it often acts as a pronoun ("the one that), especially a connective pronoun ("the one that") introducing a dependent clause.  The form that works best here is "what" because the gender is neutral.

things -- (WN) This seems to indicate a that the word above is plural, but it is singular.

which -- This comes from the demonstrative pronoun introducing a dependent clause.

he -- This comes from the singular, third person of the verb.

saith -- (CW) The Greek word translated as "say" is not the ordinary "to say," "to talk," "to tell," or "to speak" in Greek. This word means "idle chatter," "gossip," and "the proclamations of an oracle." Jesus uses it to capture the idea of "passing on." "conveying,"  or "relaying" information.  When there isn't an object, "transmit" captures the idea of being a conduit rather than a source of information.

shall -- (IW) The following verb is neither in the future tense nor in a form of possibility so this word doesn't make much sense here.

come to pass; -- The word translated as "come to pass" means "to become," that is, to enter into a new state. In Greek, especially as used by Jesus, it is the opposite of "being," which is existence in the current state. When speaking of events, this word means "happens," which seems to be the sense here.

he -- This comes from the third person, singular form of the following verb. But since the subject seems to be "what happens," an "it" is better. However, the "have" below reverses its meaning.

shall -- This comes from the future tense of the following verb.

have -- The verb translated as "have" here is the common form of "to be" in Greek. It means to have a certain characteristic or remain in a certain condition. However, when it takes an indirect object, the literal "it is to him" becomes "he has it, or the indirect object can act like a possessive, "it is his."  The tense is the future.

missing "it"  -- -- (MW) The word translated as "him/it" is the Greek word commonly translated as third-person pronouns in English.  The word means "the same" when used as an adjective. In the adverbial form, it  means "just here" or "exactly there." The form of this word requires the addition of a preposition in English to capture its meaning, a "to" as an indirect object, a "with" for instruments, an "in" for locations, "for" a benefit, an "as" for purposes, an "of" for possession, a "by" for agents, an "as" for comparisons, and an "in" for area of effect.

whatsoever he saith.  -- (OS) There is nothing in the Greek that can be translated as "whatsoever he saith" in the source we use today but it does exist in the source that the KJV translators used. OS -- Outdated Source -- The Greek word translated as "whatsoever he saith" existed in the KJV Greek source but not the source we use today.