For many will come in my name, claiming, ‘I am the Messiah,’ and will deceive many.

For  - The word translated as "for" can be treated as supporting a dependent clause, or, to prevent a run-on sentence, translated as a "this is because..." to start a new sentence.

many  - The word translated as "many" means many in number, great in power or worth, and large in size.

will -- This helping verb "will" indicates that the verb is the future tense or a form that indicates possibility at some time. Helping or auxiliary verbs are needed to translate the Greek verb forms into English.

come  - The word translated as "come" primarily means "to start out." It indicates movement, especially its beginning, without indicating a direction toward or away from anything, so it works either as "start," "come," or "go," but it is more like our phrase "being underway." Christ, however, uses it most often, but not always, in the sense of "come." It is in the future tense.

in  - The word translated as "in" means "upon," "against," "before," "by" or "on." It is NOT the word Jesus  most commonly uses with the Greek phrase usually translated "in" someone's name. See this article on all the formulations of this phrase and their possible meanings.

my -- "My" is the first-person possessive singular pronoun. This pronoun follows the noun so "of mine."

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. 

name,  - The Greek word translated as "name" is much more complicated than it might at first appear. It can simply mean a "name" as in English, this can be many things. It doesn't mean the thing itself, but what people call it. For example, it can mean a "false name," or "a pretense" as we say "this is a marriage in name only." It can also mean representing another person's authority, as we say, "he is acting in the name of the boss" or, in this case, "against the name."

claiming,  - (CW) The word translated as "claiming" 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. However. it also means "to proclaim," which is how it usually works best when Christ puts it in the mouth of his opponent.

I  - The pronoun "I" is added to add emphasis that he is referring to his own words. It is unnecessary because the first person is part of the verb ending. Christ sometimes uses it humorously to refer to himself. However, when you put the accent on "I" when you speak this phrase, it makes the statement sound like a claim his opponents are saying about themselves, not about Christ.

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

am  - The verb here is the common form of "to be" in Greek in the first person, present form.

the -- The word translated as "the" 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.

Messiah;  - The word translated as "Christ" means "the anointed." In the NT, it is understood to mean the Messiah, following the tradition of the anointing of the kings of Israel.

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

will -- (CW) This helping verb "shall" does not indicate the future tense, but that the 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.

deceive  - "Deceive" is from a verb that means "to cause to wander," "to lead astray," "to mislead," "to wander," "to stray," and "to be misled." The form indicates something that "might" or "possibly happens. It is could be in the future tense, but its form is also tense indicating something that might happen at a point in time.

many.  - The word translated at the end of the verse as "many" means many in number, great in power or worth, and large in size. It is the same word that began the verse.