I've not grown any bulbing onions, but 4" seems too close for spacing to me. Expecting (hoping) for 3-4" bulb diameters I would double your spacing to 8". Just my thoughts.

They are about 5 or 6 inches apart in rows. The rows are 1 foot apart. That's how I planted them last night. Thanks for your time,

David

my grandma said she has grown onions before and that they only take about 3 or 4 weeks.

This seems like a very short amount of time. I bought my onions online and this is what their site states.

"Since they are planted in the South during the winter or early spring months, they take approximately 110 days to mature. When planted in northern states in late spring, they mature in just 75 days, but produce smaller bulbs. The earlier you plant them, the larger they get."

My suggestion is to pull one onion a week to track their progress.

David,
You need not pull any onions to check their progress,They will appear to climb up out of the earth as they swell. If your soil is not loose enough, you may need to gently pull some of the dirt away from the bulb as it gets larger.
Indeed, 3 or 4 weeks will not even get you green onions, although sets will grow somewhat faster than seed or transplants. Sometimes sets go to seed rather than make bulbs.
Next time I would recommend that you plant seed for transplants or buy tranplants suitable for your lattitude. Even then, some varities will go largely to seed. If there is anyone in your area who grows onions, check and see what varitie/s they grow.

Here is a link that might be useful: information about growing onions

You might want to look at this site, they have a lot of information about growing onions and what is the right onion for your section of the country

Here is a link that might be useful: Dixondale Farms