Birches
Truth broke in
Frost capitalizes Truth like a person interrupting his fantasy. He's staging the poem as a conflict between what he wants to believe (the boy) and what actually happens (ice-storms).
Launching out too soon
The physics: climb too high before the tree bends, you go down with it and hit hard. Wait for the bend, you ride it safely. The boy learns timing through trial and error.
Half grant what I wish
He's afraid of actual death—being taken to heaven permanently. The whole poem hinges on temporary escape, not permanent exit. 'Half grant' would mean dying instead of just getting a break.
Half grant what I wish
He's afraid of actual death—being taken to heaven permanently. The whole poem hinges on temporary escape, not permanent exit. 'Half grant' would mean dying instead of just getting a break.
Black branches, snow-white trunk
Birch trees actually have white bark and dark branches. This isn't metaphor—it's the literal color reversal you see climbing up a birch in winter.