Grade a whole class' worth of tests＝１クラス分のテストを採点する
grade＝採点
a 〜's worth＝〜の分
I did a week's worth of grocery shopping today＝今日は一週間分の買い物をした
a whole class分のgradingをした、と言う意味です。上の例文のようにweekだとweek'sになりますがclassはsでおわるのでこう言う場合はclass'と書きます。
I single handedly mark the tests of all the students in my class.
*I mark the tests of all the students in my class.- This is simple way of saying it.
*I single handedly mark the tests of all the students in my class. - Single handedly means to do something without anyone's help.
*I mark the tests of all the students in my class.
（クラス全員分の採点をする）
これが一番簡単な言い方です。
*I single handedly mark the tests of all the students in my class.
（一人でクラス全員分のテストの採点をした）
”Single handedly”というのは、誰の助けも借りずに一人でやるという意味です。
I have to grade the papers of all the students in my class.
1. I have to grade the papers of all the students in my class.
This means that the teacher has to correct the work of all the students submitted to the
teacher.
1. I have to grade the papers of all the students in my class.
（私はクラス全員分のテストの採点をしなければいけない）
これは先生が生徒が提出したテストを採点し、直さなければいけないという意味です。
"I have to mark all of the tests for my class." This explains that you have to grade all of the test papers for your class.
"I have to grade my whole classes test papers." This is another way of explaining that you have to mark and check all of the papers for your class.
“I have to mark all of the tests for my class.”
(私は自分のクラスの全部のテストを丸つけしなければなりません。)
これは、クラスのテスト用紙の丸つけをしなければならないことを表しています。
“I have to grade my whole classes test papers.”
(私は自分のクラスの全部のテストを丸つけしなければなりません。)
これも、クラスのテスト用紙の丸つけをしなければならないことを表現する別の方法です。
I have to grade the tests of all the students in my class.
I grade all the tests written by the students in my class
I grade the tests of all the students in my class
When you want to explain that you have to mark/grade the tests of all the students in your class, you can say it in the following ways:
-I have to grade the tests of all the students in my class.
-I grade all the tests written by the students in my class
-I grade the tests of all the students in my class
自分のクラスの生徒全員のテストを採点しなければならないと伝えたいなら、以下のフレーズが使えます：
I have to grade the tests of all the students in my class.
（私のクラスの生徒全員のテストを採点しなければなりません。）
I grade all the tests written by the students in my class.
I grade the tests of all the students in my class.
（私のクラスの生徒全員のテストを採点します。）
Context is important and it really depends on why you are making this statement. Are you worried that someone else may do the marking in place of you? Has someone asked you to mark all the tests for all the school classes?
I have to mark/grade all the tests for all the students in my class
I single handedly mark/grade all the students tests in my class
I have to grade/mark all my class's tests
A simple way of explaining it is ' I have to mark/grade all my class's tests'
To do something single handedly means that you do it on your own with no one else's help
シンプルに説明するのであれば、
'I have to mark/grade all my classes tests'
（クラス全員のテストを採点しないといけません。）
と言えます。
"single handedly"は、誰の助けも借りず自分1人でやることを表します。
アメリカ合衆国 
南アフリカ 
カナダ 
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