# "People decrease" or "The number of people decrease"?

I'm writing a formal technical report. I'm bit confused about how to use "decrease".

The report discusses the shift in the number of people heading home in the evening.

I'd like to say "the number of people who go their home slowly decrease(s?) after 6 pm".

Which is the correct expression?

The number of people who go their home slowly decrease after 6 pm

People who go their home slowly decrease after 6 pm

I'm also worried about the relatively long subject in this sentence. Is "The number of people who go their home" too long for a subject? My teacher says shorter subjects are better in English writing.

• It's worth noting that "people" is not a collective noun when used in this way. See this answer for more. Apr 2, 2016 at 16:34

You could simplify the first sentence like this:

The number of people going home decreases slowly after 6 pm.

Decrease requires an s because we are talking about a number (singular) not the people (plural). slowly should be after the verb so that the reader doesn't visualise people walking slowly.

The number of gives important information, and should be included for clarity. If you leave it out, it sounds like each person gets smaller after 6pm. This meaning is not grammatically correct because a person cannot decrease, but an impression of the incorrect meaning may appear in the reader's mind if you do not start the sentence correctly.

Both of your examples are correct and mean the same thing (note: spelling and word position changes):

The number of people who go home decreases slowly after 6 pm
People who go home decreases slowly after 6 pm

meaning the volume of people gets less after 6 pm.

Using

The number of people who go home slowly decreases...

may be understood to mean the people travelling slowly decreases, not the total volume

• Thank you very much! Great answer. I'm bit confused about the difference "the people travelling slowly decreases" vs "the travel volume". I'd like report the reduction of the total amout of people's travel during given hour. I mean, for instance, 1,000 people leave for home between 6:00 to 7:00, 950 people leave for home between 7:00 to 8:00, and 900 people do between 8:00 to 9:00, where decrease is slow from 1,000, 950, and 900. Sorry for very redundant explanation due to my limited English skill. :) Apr 2, 2016 at 2:04
• In the second sentence, is it necessary to add 's' even 'people' represent more than two persons? Apr 2, 2016 at 2:08
• In the second sentence "the number", "the amount of", or "the many" is left out but understood. Apr 2, 2016 at 3:14
• The added "s" in the second sentence is wrong. Apr 2, 2016 at 14:42