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.

wheresoever  - The "wheresoever" is from a word that means "somewhere," "anywhere," "wherever," and "where."

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."

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. 

carcase  - (MM) "Carcase" or "carcass" is translated from a Greek word that means a "fall," "injuries from falls," or "fallen body" so a "corpse." This word was a common metaphor for "misfortune" and "calamity." It has a definite article, "the," so "the fall" or "the calamity." It means the result of a fall more than the act of falling. It is one noun form of the common verb used above meaning "to fall." This is the only time this word is used by Jesus. He uses another word describing the act of falling only once as well in Matthew 7:27.

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. It also equates terms or assigns characteristics. 

there  - "There" is a word meaning "there," "in that place," and in philosophy means "the intelligible world."

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

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. 

eagles  - (MM) Eagles" is from the Greek word for "eagle," "bird of omen," or "omen." It is a Greek word, but this word was used in the Septuagint to translate the Hebrew word for "eagle" (nesher), which means both "eagle" and "vulture." Among the Jews, it was forbidden to eat eagles, along with buzzards and vultures, so they were grouped among carrion birds. Some uses of this word, such as Micah 1:16, which refers to the baldness of eagles, clearly referring to vultures, which are bald. (Bald eagles, of course, are not bald but have white feathers on their adult heads and were not known in the ancient world.) While there are positive characteristics of eagles in Jewish writing, based on their size and strength. This view of eagles in the West is positive, but this comes from Greek and Roman culture, which had a very positive view of the bird, but they also saw eagles as a bird of omen.

be-- This helping verb "be" indicates that the verb is passive. Helping or auxiliary verbs are needed to translate the Greek verb forms into English.

gathered  - The Greek word translated as "will be gathered together" means "to bring together." It is the word used both for gathering crops and bringing animals in from the fields. One of its noun forms that is familiar is "synagogue" which means "meeting place" in Greek. It is in the passive, which means something is gathering the vultures together. The form does not indicate that they are gathering themselves.

together. -- This is from the prefix of the previous verb that means "toegther."