Watch  - "Watch" is from a verb that means "to be or to become fully awake." It is in the form of an command "be fully awake". In English, we would say "wake up" to someone sleeping and "stay awake" to someone already awake. In the last few chapters, the original Greek focuses on the idea being awake and ready. In English, this is lost because the term for awake is often translated as "watch."

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

pray, - The word "pray" means "to offer prayers" to God. However, in this form, it has the sense of praying for your benefit.

so that -- The word translated as "that" is an adverb "in that place," "there," "where," "when," or as a conjunction that starts a subordinate clause  "that," "when," "in order that" or "because."

you -- This is from the second-person, plural form of the verb.

will -- (WW) This helping verb indicates that the verb is the future tense, but it isn't. It is in the form of possibility so it needs a "should" or "might."

not --  The negative used here is the Greek negative of a subjective opinion, commands, and requests. The sense is that "you don't want" or "think" something, not that it isn't done or thought.  The "will," though it creates the wrong tense does capture some of this feeling.

fall - -  (WW) "Fall" is a word that means "go or come into" and has the double meaning of "coming into one's mind." It is in a form indicating something that "might come into." It doesn't mean "fall," a word that is used because "trial" is turned into "temptation."

into  - The word translated as "into" means "into" a place, "towards" as a direction, and "up to" limits in time and measure.

temptation: - (CW) The Greek word translated as "temptation" doesn't primarily means that. It means a "trial" as in a "worry." Christ doesn't use this term but another Greek word to refer to court trials. It could mean a "trial" as a "test." Again, this is an uncommon word in Christ's teaching.

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. 

spirit  - - The word translated as "spirit" has been used in the section to mean "non-material beings" but it primarily means "breath", "wind," and "blast." Like "spirit" in English, it can also mean "attitude" or "motivation.' Its meaning as "the breath of life" is brought out by the idea of creating life. Its meaning as "spiritual" is brought out by the contrast with "physical". Read this article on the use of this word with "holy" and this article when contrast with similar terms for the soul, life, and mind.

missing "on one hand"  -- (MW) The untranslated word "indeed" here is a particle, which. when used alone. expresses certainty, "truly" and "certainly". However, when used with the conjunction translated here as "but" takes on the meaning "on one hand..." with the "on the other hand" identified by the "but" phrase.

is -- There is no verb "is" in the Greek source. It is implied by the equating of "workman" with "worthy" both in the Greek form of subjects.

willing, The term translated as "willing means "ready", "willing", "eager", "bearing goodwill", "wishing well," and "readily." This is an uncommon word from Christ to use.

but  - The "but" here is the particle frequently translated as the English conjunction "but" but this word has a number of specific use, one of which is to indicate the other half of a contrast where the first half is indicated by the word translated "indeed" above. The meaning here becomes "on the other hand."

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. 

flesh The Greek word translated as "the flesh" means "flesh", "meat," and "the physical order of things" as opposed to the spiritual. In contrasting it with "spirit," he is making it clear that he has been using it in the later sense. It is not the word that Christ uses for "body" in Matthew 26:26 (discussion here). The "body" is the physical part of a person without their soul, but in the Greek the word for "flesh" here has an even lower sense, that of being just meat, but Christ doesn't use it that way. He uses this word "flesh" as of the physical existence and relationships between people. It is used somewhat sparingly by Jesus in Matthew (Matthew 16:17, Matthew 19:5), Matthew 24:22 but Christ uses it heavily in John sometimes to equate his own body with the flesh of food. For Christ, the word captures the abilities of the physical body, those we share with animals.

is -- There is no verb "is" in the Greek source. It is implied by the equating of "workman" with "worthy" both in the Greek form of subjects.

weak.  - The word used for "weak"" means "without strength," "weak", in body "feeble", "sickly", in power, "weak", "feeble", in property, "weak", "poor", and "insignificant." It was translated as "sick" in Matthew 25:43, in the sense of "I was sick and you visited me."