Verily, -- The word translated as "verily" is from 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." See this article discussing this "amen phrase."

verily -- The word translated as "verily" is from 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." See this article discussing this "amen phrase."

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 Christ 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." Christ usually uses this word to refer to his own speaking or teaching.

unto -- This word "unto" comes from the dative case of the following word that requires the addition of a preposition in English, but the translator must decide which preposition to use: a "to" as an indirect object.

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

I -- The pronoun "I" is used here. Since, as the subject of the sentence, it is part of the verb, its explicit use accentuates who is speaking "I." Saying "I myself" captures this feeling in English.

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 "am" 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.

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. 

door -- The word translated as "the door" means "door," "valve," "gate," "window shutter," "a frame of planks," [in war}"fence or similar obstruction," "entrance" and, metaphorically, "entrance to the soul." This term for "door," is used by Jesus only here in the synoptic Gospels, but which is used in John more frequently by Jesus referring to himself as "the door" to salvation.

of -- This word "of"  comes from the genitive case of the following word that requires the addition of a preposition in English.  The most common is the "of" of possession.

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. 

sheep.-- "Sheep" is Christ's symbol for his followers. The Greek word refers to any domesticated animal and works better if translated simply as "flock" or "herd." The flock follows the shepherd, which is above them. It is also together, a united group.