Quote Originally Posted by Throbert McGee View Post
Домой is actually an adverb, meaning that it doesn't decline or show gender, etc. -- it's always домой. And it means "to one's own home", or "homeward", etc.
Yes. This is the most exact translation.

домой=homeward

Quote Originally Posted by Throbert McGee View Post
The noun дом can often be translated "house; home", but in some contexts it can mean simply "a building." So if you said Я иду в дом (with дом in the accusative) it would generally be understood to mean "I'm going into the building." But Я иду домой has the clear meaning "I'm going home; I'm going to my own house" (not into some other building, and not into someone else's home). The same basic distinction applies to the adverb дома ("at home, in one's own house") versus the prepositional/locative phrase в доме ("inside a building").
There is no locative for "дом". There is a vestige of the former locative case in the frozen phrase "на дому" but it is currently considered a two-word adverb rather than locative because you cannot insert an adjective between "на" and "дому".


Quote Originally Posted by Throbert McGee View Post
For example, "I was sitting in the chair" (location without movement) would be Я сидел на стуле (with the word for chair in the prepositional/locative form).
Again, this is not locative. It is prepositional. The locative form would be "на стулУ". But is is not used.