"Delhi's winter is marked by very dense fog and haze, which

[tufguy]

"Delhi's winter is marked by very dense fog and haze, which dramatically reduce visibility and makes days colder by cutting off sunlight."

I read it on the internet but I am confused a bit.

They didn't write "Reduces" after dramatically because they were writing about two things "Dense fog and haze". Am I correct? However they wrote "Makes" right after "And". So, could you please explain why they did this? They should have used "Make" instead of "Makes" because they were referring to "Fog" and "Haze".

Please explain.

 

[emsr2d2]

Yes, it should be "make".

 

[Tdol]

You could think of them as one thing (general air pollution) and say reduces/makes too.

 

[tufguy]

You could think of them as one thing (general air pollution) and say reduces/makes too.

Okay so if I talk about two things like "Dipression and anger don't let you think positively" so can I also say "Dipression and anger doesn't let you think positively". Can we think about two or more things as one unit? Is it correct to do so?

 

[tedmc]

Okay, so if I talk about two things like "Depression and anger don't let you think positively", [STRIKE]so[/STRIKE] can I also say "Depression and anger doesn't let you think positively"? Can we think about two or more things as one unit? Is it correct to do so?

Unlike "fog and haze" which are closely related, "depression and anger" and two different emotions, so I would use the plural.

 

[Charlie Bernstein]

Okay, so if I talk about two things like "Depression and anger don't let you think positively", can I also say "Depression and anger doesn't let you think positively". Can we think about two or more things as one unit?

Rarely.

Is it correct to do so?

Tdol is making an interesting point, but it's safer to just treat two things as two things and use plural verbs: Fog and haze pollute; depression and anger make you think bad thoughts.

Keep it simple.