もう
In "もう一度", "もう" contributes the meaning “again.” Together with "一度", it asks the listener to repeat something. A reusable pattern is "もう一度" + an action when asking for one more repetition.
一度
In "もう一度", "一度" means “one time” or “once,” and the whole expression means “again” or “one more time.” It is used here to specify that the listener should say something one more time. A reusable pattern is "一度" + an action to refer to doing something once.
言って
"言って" means “say” or “tell” here and is used before "ください" in "もう一度言ってください". It is the form of "言う" used to make a polite request with "Vてください". Use this pattern when asking someone to say something.
ください
"ください" makes the preceding action into a polite request. In "もう一度言ってください", it makes the request “Please say it again,” and the same function appears in the other requests in the dialogue. A reusable pattern is an action in the て-form + "ください".
それ
"それ" means “it” or “that” in "それを書いてください". It refers to the thing the speaker wants the listener to write. A reusable pattern is "それを" + an action when referring to that object.
を
"を" marks "それ" as the object of the action in "それを書いてください". It shows what is being written. A reusable pattern is a noun or pronoun + "を" + an action.
書いて
"書いて" means “write” here and is used before "ください" in "それを書いてください". It is the form of "書く" used for a polite request. Use the pattern action in the て-form + "ください" when asking someone to write something.
私
"私" refers to the speaker as “I” or “me” in "私に見せてください" and "私を手伝ってください". The following particle shows its role: "私に" is the person something is shown to, while "私を" is the person helped. Use "私に" or "私を" according to the action and its relationship to the speaker.
に
"に" marks the person who receives or is directed toward an action in "私に見せてください" and "私に電話してください". Here it can be understood as “to me.” A reusable pattern is a person + "に" + an action directed to that person.
見せて
"見せて" means “show” here and is used in "私に見せてください" to ask someone to show something to the speaker. It is the form of "見せる" used before "ください". Use the pattern a person + "に" + "見せてください" when asking someone to show something.
手伝って
"手伝って" means “help” or “assist” in "私を手伝ってください". It is the form of "手伝う" used before "ください" to make a polite request for help. A reusable pattern is a person + "を" + "手伝ってください" when asking someone to help that person.
何
"何" means “what” in "何を手伝いましょうか". It asks what kind of help is needed. A reusable pattern is "何を" + an action when asking what should be done.
手伝い
In "手伝いましょうか", "手伝い" contributes the meaning “help” and comes before "ましょう". It is the form of "手伝う" used in this offering. Use the pattern verb stem + "ましょうか" when offering to do an action.
ましょう
"ましょう" expresses an offer or suggestion to do something. In "手伝いましょうか", it helps form the offer “Shall I help?” A reusable pattern is an action before "ましょうか" when asking whether you should do something.
か
"か" marks "手伝いましょうか" as a question. Here it turns the offer into “Shall I help?” or “How can I help?” A reusable pattern is a question or offer ending in "か".
あとで
"あとで" means “later” in "あとで私に電話してください". It tells the listener when to make the call. A reusable pattern is "あとで" + an action when an action should happen later.
電話
"電話" refers to a phone call in "電話してください". Together with "して", it forms "電話して", meaning “make a phone call” or “call.” A reusable pattern is "電話して" + "ください" when politely asking someone to call.
して
"して" is the form of "する" used after "電話" in "電話してください". Together, "電話して" means “call” or “make a phone call,” and "ください" makes it a polite request. Use the pattern noun + "して" + "ください" for a polite request to do an action expressed with that noun.