When you hit puberty, your breasts grow larger (if you are a girl) and your hips more curvy and wide. For boys, they generally become more masculine and tall.
Not necessarily. He may just be a masculine boy.
Many of them you just have to memorize. As you practice more, you will become more familiar with what words are masculine and feminine, and it will become second nature to you. The Related link below has some helpful hints on the subject.
no usually when you have a growth spurt you become more fit developing height and becoming more masculine
A girl can become more busty by becoming more arrogant and bold. In addition, her attitude and personality will have to be more confident. She will have to dress differently, too.
When a girl says you have girly lips, it means she thinks your lips are more feminine looking than masculine looking. This is just her opinion.
My sons name is Jesse, which I feel is the masculine version. I've always seen "Jessie" as short for Jessica. I HATE it when people spell his name with an "ie". Very annoying. He's not a girl!
Talk to her more, become her friend and see what happens from there
amigo - boy amiga- girl
shelby is more a lastname than a first name so male and female may be a shelby
Shadow can be used as a girl's name, though it is more commonly associated with a gender-neutral or masculine connotation. Names like Shadow provide a sense of uniqueness and individuality regardless of gender associations.
It depends on the subject. If you are talking to a girl, use "you" as feminine. If you are talking to a a male or both, you use the masculine