Crane very deliberately uses categorical descriptions to label or name his characters. Henry is always referred to as "the Youth," (unless he is directly engaged in dialogue). The other main characters are "the Tall Soldier," "the Loud Soldier," "the Tattered Soldier," and "the Cheery Soldier." We occasionally learn character’s actual names, but they are never referred to as such by the narrator. Crane obviously wanted us to think of these characters as humans, but also as nameless entities caught up in something so large that it obliterated their individuality. These men do have distinct personalities that are distinguished by their mannerisms, actions, and attitudes; however, many of these distinctions are rendered moot in battle, and especially in death. War, according to Crane, is the great leveler. Humans can be themselves, but their unique feelings and thoughts do not matter in the field of injury and death. Every man is equally capable of killing and being killed.
Everyone in the novel speaks with the same small-town, uneducated, early 1800s dialect. When Henry is leaving for the army, his mother says:
An' allus be careful an' choose yer comp'ny. There's lots of bad men in the army, Henry. The army makes 'em wild, and they like nothing better than the job of leading off a young feller like you, as ain't never been away from home much and has allus had a mother, an' a-learning 'em to drink and swear. Keep clear of them folks, Henry. I don't want yeh to ever do anything, Henry, that yeh would be 'shamed to let me know about. Jest think as if I was a-watchin' yeh (1.28).
Everyone in the novel speaks this way (although the colonels and generals of the army tend to use slightly more correct grammar). The soldiers use realistically idiomatic English that reflects both the time period and the level of education of the general populace. They also call each other hilarious things like "lunkhead" and "jimhickey" and "jim-dandy," and insist on saying "by thunder," and "by ginger" – which mean who knows what but are rather enjoyable to read anyway.