as many people as
Hagowingchun

October 12 at 08:56
There aren't as many people in my family as Susan's. (correct)
your second sentence needs a missing (as)
My family doesn't have (as) many people as Susan's.
Just add the as in parathesis to your sentence and its good to go.
lilyyang

October 12 at 09:36
Thank you so much for the help.
Another situation pops up in my head.
I went hiking for three hours. And Susan went hiking for five hours.
Is it okay to say:
Susan went hiking longer than me.
or
I didn't go hiking as long as her.
Hagowingchun

October 12 at 12:13
Susan went hiking longer than me. and I didn't go hiking as long as her. are good.
ZayaFTW

October 12 at 05:52
Hey!
You're able to say:
☑ "There aren't as many people in my family as Susan's."
↑ That makes sense to me.
☑ "My family doesn't have as many people as Susan's does"
↑ This one makes sense to me and works too
You can't say
☒ "My family doesn't have many people as Susan's."
You have to put another as after in order to have it make the most sense.