Can I screw a US garden hose into any standard threaded pipe?
No, a US garden hose thread is its own thing.

This table has a useful comparison:



Note that the hose thread (called "GHT" in plumbing circles) clearly does not match ANY of the other thread specifications in this table of common sizes. I circled some table entries with the closest dimensions to GHT just for emphasis.

Though it's "3/4" diameter is nearly the same as several others, the threads-per-inch are quite different. 

I suppose that the designer wanted it to screw on with fewer turns, hence the low TPI count for the common 3/4 size. Maybe this makes manufacturing tolerances easier also.

So the only way to make a screwed-together attachment is to use an appropriate spigot, bibb, or adapter.