An -- There is no indefinite article in Greek, but when a word doesn't have a definite article, the indefinite article can be added in English translation.

evil  - The word translated as "evil" means "second-rate" or "worthless." This article explores its meaning in more detail. It is an adjective, but when used as a noun, therefore, "what is worthless."

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

adulterous  - (WF) "Adulterous" is a Greek noun meaning "an unfaithful woman." It is in the same form as the noun ("generation") implying that they are equivalent. The word means  It is a metaphor for those unfaithful to God. It is not an adjective.

generation  - "Generation" is a Greek word that means "race," "family," "offspring," and "age." It is the root for our words "generic," "genus," as well as generation. Christ uses it to describe a certain of person as well as a certain type of people.  It always appears in the singular as do all the words referring to it. 

seeks  - "Seeks after" is a verb that means "to seek after," "to wish for," and "to demand."

after -- This is from the prefix of the previous verb that means "upon," "after" and so on.

a -- There is no indefinite article in Greek, but when a word doesn't have a definite article, the indefinite article can be added in English translation.

sign;  - "Sign" is Greek word that means a "mark," "sign," or "proof." The word in Greek is used specifically to means a sign from the gods and it that sense, it means "omen," "portent," and "constellations."

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

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

no - (WP) The Greek word translated as "not" is the Greek negative used to deny objective facts, not opinions. It means "no," "not," or"no truly." This word negates the verb, not the word "sign"

sign - "Sign" is Greek word that means a "mark," "sign," or "proof." The word in Greek is used specifically to means a sign from the gods and it that sense, it means "omen," "portent," and "constellations."

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

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.

given - The verb translated as "given" means "to give," "to grant," "to hand over," "appoint," "establish," and "to describe." It is almost always translated as some form of "give." The word is future passive.

to -- This word "to" comes from the dative case of the following word that requires the addition of a preposition in English. The most common is a "to" for the English indirect object.

it -- The word translated as "his" is the Greek word commonly translated as third-person pronouns in English.

but - (CW) Two Greek words are translated as "but." Literally, they mean "if not" but this phrase is used to mean "except," "instead," and "but." 

the -- The word translated as "the" is the Greek definite article. The Greek article is much closer to our demonstrative pronouns ("this," "that," "these," "those") than the English "the." See this article for more. 

sign - "Sign" is Greek word that means a "mark," "sign," or "proof." The word in Greek is used specifically to means a sign from the gods and it that sense, it means "omen," "portent," and "constellations."

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. The Greek article is much closer to our demonstrative pronouns ("this," "that," "these," "those") than the English "the." See this article for more. 

prophet -- (UW) The Greek word translated as "prophets" means "one who speaks for God," "interpreter" and was the highest level of priesthood in Egypt,, but its root words mean "shine light before" and so "shining lights" or "enlightened" seems to capture the idea better. Jesus uses it to refer not only to divine spokespeople, but their books in the OT. It is the verb that means "to shine before." Our word "luminaries" captures the idea very well.  It is the untranslated Greek word adopted into English. Read this article for more information.

Jonas: -- "Jonas" is from the Greek spelling of the proper name "Jonah."