几个基础的英语问题The giri is my sister 这个句子中the 是不是定语；还有状语怎么区分,它修饰句子

楼主首先要明白一个概念：句子成分.你所说的定语、状语还有谓语等等都属于句子成分.The giri is my sister 这个句子中the不叫定语,它的词性是定冠词,表示后面所修饰名词是说话双方都知道的,明确的或者是特指的.给楼主附上巧记定冠词the用法歌诀：
特指双方熟悉,上文已经提起.
世上独一无二,方位名词乐器.
某些专有名词,还有复数形式.
序数词最高级,习惯用语牢记.
至于状语,一般修饰动词、形容词、副词等的句子成分叫状语（adverbial).
状语的功用：状语说明地点、时间、原因、目的、结果、条件、方向、程度、方式和伴随状况等.
状语一般由副词、介词短语、分词和分词短语、不定式或相当于副词的词或短语来担当.其位置一般放在句末,但也可放在句首或句中.
副词是一种用来修饰动词,形容词,副词或全句的词,说明时间,地点,程度,方式等概念.举几个例子：
1.副词一般在句子中做状语．
He speaks English very well.他英语说得非常好.
He is playing under the tree.中的under the tree(地点状语)
2.不定式在句子中可以作目的状语.
I come specially to see you.我专门来看你.
3.介词短语
My parents often tell us about their bitter life in the past.
Ten years ago,She began to live in Dalian.
The boy was praised for his bravery.
4.从句作状语
When she was 12 years old,she began to live in Dalian.
If I am not busy tomorrow,I will play football with you.
5.分词作状语
Having had a quarrel with his wife,he left home in a bad temper.
Inhibited in one direction,it now seems that the Mississippi is about to take another.

定冠词the，是特指某人某事。句子里面随处可见。没有特别修饰什么成分。

这是定冠词the 不表修饰，是表特指，这个，这个女孩，而不是那个，还有，如果前文有提过这个女孩子的话，后面想提这个女孩的时候，要在前面加the

不是定语，是定冠词