Note
This guy is so big that everywhere he goes, there's only space for one person.
Usages of big
A dog is basically just a big dot running around.
Heaven is one hell of a big place.
You have a big gun that shoots arrows.
There's a new type of book, with each page made from big grains of rice.
The people in the center of power always cover up big things.
When you're curious, even big things become possible.
A calamity bends our life in a big way.
Even if you bend the upside down box, the rice is simply too big to fit in its interior.
You carve a big mark as a sign of your pledge.
大きさ is more general than サイズ. For shoes, clothes and other items that come in standardized sizes, it's more common to hear サイズ.
You have a big archery glove.
Grass must not be in the sun too much until it is big.
Your enclosure plays a big factor in your contentment.
You participate privately in big hair festivals.
