状语可以由副词, 副词，介词短语，
不定式和从句等来担任。状语一般放在被修饰的词之后或放在句尾。副词作状语时可放在被修饰的词前或句首。
We went to the countryside last year.
I often read the news paper at night.
状语在句子中的位置很灵活，常见情况为：通常在句子基本结构之后，强调时放在句首；修饰形容词或副词时，通常位于被修饰的词之前；表示时间、地点、目的的状语一般位于句子两头，强调时放在句首，地点状语一般须在时间状语之前；一些表示不确定时间（如：often）或程度（如：almost）的副词状语通常位于
be动词、助动词、
情态动词之后，动词之前。
有时状语在句中的某个位置会引起歧义，应注意，如：The boy calls the girl in the classroom.一般理解成‘男孩喊教室里的女孩‘（此时in the classroom为girl的定语），也可以理解为‘男孩在教室里喊女孩’（此时in the classroom为地点状语），最好写作‘In the classroom, the boy calls the girl.'
副词（短语）作状语：
The boy needs a pen very much（程度状语）
The boy needs very much the pen bought by his mother.（宾语较长则状语前置）
The boy really needs a pen.（程度状语）
The boy needs a pen now./Now, the boy needs a pen./The boy, now, needs a pen./男孩现在需要一支钢笔。（时间状语）
介词短语作状语：
In the classroom, the boy needs a pen.（地点状语）
Before his mother, Tom is always a boy.（条件状语)
On Sundays, there is no student in the classroom.（时间状语)
分词（短语）作状语：
He sits there, asking for a pen./ （表示伴随状态）
Having to finish his homework, the boy needs a pen./（原因状语）
Frightened, he sits there soundlessly./ （原因状语）
不定式作状语：
The boy needs a pen to do his homework.（目的状语）
To make his dream come true, Tom becomes very interested in business./
名词作状语：
Come this way!/ （方向状语）
状语从句：时间状语从句/地点状语从句/原因状语从句/结果状语从句/目的状语从句/比较状语从句/
让步状语从句/条件状语从句