Question regarding 'a quantity of' and 'a mass of'

Test Preparation
1

<p>Hi,</p>

<p>Shall I say 'there is a large quantity of people' or 'there are a large quantity of people'?
similarly, can I say 'there is a mass of cells' or ' there are a mass of cells?'</p>

2

<p>Large MASS or large NUMBER of people. Quantity sounds awkward when used to describe people.</p>

<p>Use “is” because mass & number are singular. “People” is not the subject; it is the object of the preposition “of”.</p>

3

Thank you so much !