Get thee behind me, Satan: for -- (OS) There is nothing in the Greek that can be translated as "Get thee behind me, Satan: for" in the source we use today but it does exist in the source that the KJV translators used.

It -- This is from the third-person, singular form of the following verb.

is -- (WT) This helping verb "is" indicates that the following verb is passive. Helping or auxiliary verbs are needed to translate the Greek verb forms into English. However, the tense here is the past perfect, so "has been."

written -- "Written" is a verb that means "to mark," "to express by written characters," and "to write down [a law]."  The verb is passive, completed in the past, "it has been written."

Thou -- This is from the second-person, plural form of the verb.

shalt  -- This helping verb "shalt" 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.

worship -- "Worship" is from a Greek word that means "make obeisance," specifically to prostrate yourself before authority, as we would use the Chinese term, "kowtow." In the previous verse, this Greek word was used with the verb meaning "falling down." The form is either the future tense or a form of possibility, that is, what "should" happen.

the -- (WP) The word translated as "the" 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.  This word appears before "God" not "Lord."

Lord -- The word translated as "Lord," is the same as the one used to describe a master of slaves. While most references to slaves in the KJV are translated to "servants," the use of "Lord" and "slaves" is common in Christ's parables because it describes a common employment situation of his time.

thy -- The word translated as "thy" is the possessive form of the second person pronoun. This pronoun follows the noun so "of yours."

God, -- The word translated as "God" means "God" and "deity." It is introduced with an article, so "the God." Jesus often uses it this way perhaps to indicate the one God as opposed to the pagan gods. See this article for more.

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."

him -- The word translated as "him" 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." This pronoun follows the noun so "of his."

only -- "Only" is an adjective that means "alone," "solitary," "only," "single," "unique," "made in one piece," "without [someone]," "only [something]," "unique," "one above all others," and "on one condition only." This word was not a part of the original verse in the Septuagint.

shalt  -- This helping verb "shalt" 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.

thou -- This is from the second-person, plural form of the verb.

serve. -- (CW) The primary meaning of the Greek word translated as "serve" is "to work for hire," but its secondary meaning is "to be enslaved to." This is not Jesus's normal word that means "serve."