Be -- (WF, WT) The verb "is" here is the common form of "to be" in Greek. It means to have a certain characteristic or remain in a certain condition. It also equates terms or assigns characteristics It is not the form of a command, as translated. It is in the future tense. This is not the word "to become," which is often translated as "be" in the Bible referring to a change of state. The verb describes a stable state of being in the future.

ye -- (MW) The pronoun "you" is used explicitly as the subject of the sentence. Since it is already part of the verb, its use here creates emphasis on the "you" as we might say "you yourselves." It is plural.

therefore -- The Greek word translated as "therefore" has two meanings. It has the meaning of "therefore" or "then," but it also means "certainly" and "in fact." To capture its feeling, both senses of the word can be used.

perfect, -- The Greek adjective means ""perfect," "entire," and "complete" Jesus only uses it twice, and it has a lot of different meanings depending on to what it is being applied. When applied to people, it means either "accomplished," or "the best of a kind." It could also mean "without spot or blemish," but that meaning is usually applied to sacrifices. It could also mean "complete" but that meaning is usually applied to numbers. It means something completely different when applied to God.

even -- (IW) There is nothing that can be translated as "even" in the Greek source.

as -- The word translated as "as" has a very broad meaning, translated as "when," "where," "just as," "like," and related words.

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

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

Father -- "Father" is the Greek noun that means "father" or any male ancestor so "forefathers." It is the word that Christ uses to address his own Father. 

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

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

heaven  -- (WF)  The word translated as "heaven" is the adjective, not the noun, from the word for "sky." . It doesn't quite mean "heavenly" because that word is associated with the heaven of angels, clouds, and beauty generally. In Jesus's era meant, "sky" so the English adjective would be "sky" with the sense of "ethereal" and "lofty."

is -- The verb "is" here is the common form of "to be" in Greek. It means to have a certain characteristic or remain in a certain condition. 

perfect -- The Greek word translated as "perfect" at the end of this verse can only be the adjective,  because of its form. However, when this word is applied to the divine, it means "having the power to answer prayers" or "all-powerful."