fantastic
How was your weekend? It was fantastic! I went to see...
Rie did a fantastic job on this project!

afterwards  アﾌﾀｰﾜｰｽﾞ adv)後で、その後
beforehand  ﾋﾞフｫｰﾊﾝﾄﾞ adv)前もって、予め　
afterwards adv)その後=afterward≠later　later 後で
I just am talking with my friend at a cafe now.
I'll call you later.　 laterは漠然とした後
I'll call you afterwards.  友人と別れたら直ぐに電話する意
Very refreshing, I did some reading at a nice cafe and went to the gym afterwards.

I was wondering if you could come to the reception.
（控えめに頼む表現）会合に来てくれると嬉しいのだが。
reception ﾚセﾌﾟｼｮﾝ n)受付、会合

I was assigned to prepare an e-commerce market report on China.

I was instracted to prepare an e-commerce market report on China.
instruct ｲﾝｽﾄラｸﾄ v)指示する、指導する　　準備するように指示された。
I was assigned to become a mentor for a new graduate staff member.
assign ｱサｲﾝ v)割り当てる
assignment ｱサｲﾝﾒﾝﾄ n)割り当て、仕事、宿題
mentor メﾝﾀｰ n)教育係、助言者、
 an experienced person who advises and helps a less experienced person
mentoring メﾝﾀﾘﾝｸﾞ n)メンタリング　先輩社員などが新人などを指導すること
a math assignment 数学の宿題

断る（丁寧politeかつキッパリfirmと理由をつけて）
polite ﾎﾟラｲﾄ adj)思いやりのある、礼儀正しい
firm ファ-ﾑ adj)堅い、しっかりした、安定した take a firm attitude  n)会社、事務所
I'm afraid I can't help you at the moment.
I'm tied up all day with visiting clients.
client ｸラｲｱﾝﾄ n)依頼人
 a person who uses the services or advice of a professional person or organization
 We will advice the client on the best way to solve the problem.
I could do it by Friday, if it's ok with you.
I'll be happy to do just a cost analysis, if that helps.
もし足しになるなら（お役に立つかはわかりませんが）、コスト分析だけでもやりますよ。
 analysis ｱナﾘｼｨｽ n)分析    複）analyses