Question

....was at the door?(who/whom)​

Answer 1

Who was at the door?

$\bold\color{blue}{hope}$$\bold\color{red}{it}$$\bold\color{green}{will}$$\bold\color{purple}{help}$$\bold\color{orange}{you}$$\bold\color{brown}{friend}$

Answer 2

Answer:

who was at the door?

where we use who ?

• who is used to refer the subject of the sentence
• subject in grammer is who performs that action
• examples :- who would like to go on vacation ?
• Ans :- he would like to go on vacation
• here, he performs that action it means he is subject so for asking questions like this we use who

where we use whom?

• whom should be used to refer the object or position of an object
• object is who supports subject .
• examples :- by whom is the car driven to school?
• Ans :- the car is driven by Gina to school
• here we use the object first that is the car