英语定语的问题在书上看到“只能做定语的形容词little only wooden elder等,如my elder br

英语定语的问题
在书上看到“只能做定语的形容词little only wooden elder等,如my elder bro is in Beijing (正确)my bro is elder(错误）谁能解释一下（不是解释例句）再补充几个例句😣😣😣最好能用only little造句～谢

定义：　　定语是用来限定、修饰名词或代词的,定语是对名词或代词起修饰、限定作用的词、短语或句子,充当定语的有：主要由形容词担任.此外,名词、代词、数词、副词、介词短语以及动词不定式（短语）、分词和定语从句等都可用作定语.
　　形容词作定语：
　　The little boy needs a blue pen.(little修饰名词boy；blue修饰名词pen.）/小男孩需要一支蓝色的钢笔.
　　Tom is a handsome boy./Tom是个英俊的男孩.
　　There is a good boy./有个乖男孩.
　　数词作定语相当于形容词：Two boys need two pens./两个男孩需要两支钢笔.
　　The two boys are students./这两个男孩是学生.
　　There are two boys in the room./房间里有两个男孩.
　　代词或名词所有格作定语：
　　His boy needs Tom's pen./他的男孩需要Tom的钢笔.
　　His name is Tom./他的名字是汤姆.
　　There are two boys of Tom's there./那儿有Tom家的两个男孩.
　　介词短语作定语：
　　The boy in the classroom needs a pen of yours./教室里的男孩需要你的一支钢笔.
　　The boy in blue is Tom./穿蓝色衣服的孩子是汤姆.
　　There are two boys of 9,and three of 10./有两个9岁的,三个10岁的男孩.
　　名词作定语：
　　The boy needs a ball pen./男孩需要一支圆珠笔.
　　It is a ball pen./这是一支圆珠笔.
　　There is only one ball pen in the pencil box./这铅笔盒里只有一支圆珠笔.
　　副词作定语：
　　The boy there needs a pen./那儿的男孩需要一支钢笔.
　　The best boy here is Tom./这里最棒的男孩是Tom.
　　不定式作定语：
　　The boy to write this letter needs a pen./写这封信的男孩需要一支钢笔.
　　The boy to write this letter is Tom./将要写这封信的男孩是汤姆.
　　There is nothing to do today./今天没有事要做.
　　分词（短语）作定语：
　　The smiling boy needs a pen bought by his mother./那个微笑的男孩需要一支他妈妈买的钢笔.
　　The pen bought by her is made in China./她买的笔是中国产的.
　　There are five boys left./有五个留下的男孩.
打字不易,