missing "for"  -- (MW) The untranslated word "for" can be treated as supporting a dependent clause, or, in written English, as "this is because..." to start a new sentence. The "because" here naturally follows the "which" of a short question.

Which - The Greek word translated as "which" primarily means "someone" and "something," but it has a lot of uses including the introduction of short questions such as "what", "why", etc.

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.

easier, The word translated as "easier" is a compound words. It is an uncommon word, appearing only a seven  times in the NT and only five times in the rest of ancient Greek literature. The word is only used by Jesus in the NT, not other writers. The prefix here means "good" or  rather, "better," because the word is comparative. The base word primarily means "beating" or "fatigue". So the sense is "better fatigue", which has the sense of "less tiring".

to -- This "to" is added because the infinitive form of the verb requires a "to" in English.

say,  - The word translated as "to say" is the primary verb used in the NT to refer to speaking, telling, or saying. It also means "proclaiming," which works pretty well when Christ is referring to this type of statement.

Your --(WP)--- The word translated as "your" is the genitive form of the singular, second-person pronoun, which is most commonly the possessive form. However, if this were meant to describe the "mistakes," Jesus would almost always put it after that word. Here, it appears before the untranslated article and after the verb. This possibly makes it an "objective" genitive with a transitive verb where instead of inserting "of" we use words like ‘for’, ‘about’, ‘concerning’, ‘toward’ or ‘against. The sense is "being let go of you".

missing "the/this"  -- (MW) The untranslated word is the Greek definite article," the," 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," and "those"). See this article for more. 

sins  - (WW) The word translated as "sins" is a form of a word that means "to fail in one's purpose", "to neglect," and "to be deprived of." It has no sense of doing malicious evil in Greek. The best English translation is "mistake," "fault," or "failure" rather than what we commonly think of as the evils of "sin." More about this word in this article.

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

forgiven -- (WW) The word translated as "be forgiven" primarily means "to let go" or "to send away." This same word is translated as "leave", "forgive", "suffer," and "let" in the New Testament. With the word translated as "sin" it is translated as "forgive" even though it doesn't really mean that in Greek. Its form is that in which the subject is acted upon by itself. It is in the present tense so "are being let go by themselves".

or  - The word translated as "or" also means "than" in a comparison, as it is used here.

to -- This "to" is added because the infinitive form of the verb requires a "to" in English.

say,  - The word for "to say" is the same word in the same form as the earlier "to say."

Get up, - -The word for "arise" means "awaken" The word is the same word Christ uses to describe God raising the dead and false prophets arising.

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

walk? -- The word translated as "walk" means "walk around" and it is a metaphor meaning "making your way", "progress", "to use your opportunities," and "to live."