How we cite our quotes: (Act.Scene.Line)
Quote #1
Uncle, even in the glasses of thine eyes
I see thy grieved heart.
Hath from the number of his banished years
Plucked four away. (1.3.9)
Richard isn't particularly good at reading people or situations, especially before his fall from power. Here he claims that he understands Gaunt's pain, but it turns out that he's totally failed to understand Gaunt at all. His effort to make him feel better by reducing Henry Bolingbroke's banishment by four years fails pretty badly – Gaunt will be dead by then!
Quote #2
O, how that name befits my composition!
Old Gaunt indeed, and gaunt in being old. (2.1.4)
Gaunt jokes (in an incredibly sad way) that his body has come to match his name. Now that he's old, he's literally "gaunt" (thin and sickly looking).
Quote #3
Each substance of a grief hath twenty shadows,
Which shows like grief itself, but is not so. (2.2.2)
Bushy tries to convince the queen that her sense of impending doom is misplaced – he says she's confusing shadows with substance. As usual, it's Bushy who's wrong. As we know, Richard will soon be deposed by Henry, which means the queen will soon be separated from her husband.