【介词短语开头】
用介词短语开头，表示句子谓语动词发生的时间、地点、方式、原因、条件等：
On seeing him approach, the girl immediately turned her face to a shop window pretending to look at something there.(时间)
Around the corner, a crowd gathered.(地点)
Unlike his father, Peter touches neither cigarettes nor alcohol.(方式)
Due to the limit of seats, he was not accepted.(原因)
In case of fire, use the stairways.(条件)
【动词不定式开头】
动词不定式开头，强调谓语动词动作的目的：
To celebrate the arrival of the Millennium, we held a grand party in the hotel.
To show my trust on him, I deposited $ 10,000 into his bank account.
【独立分词短语开头】
用独立分词短语开头，使句子有正式的味道：
Birds singing in the tree, another routine day starts.
Sea gulls flying over the water, the old fisherman flung his fishing meat into the open sea.
A dog following them, the police searched every suspect.
【过渡句开头】
用过渡句开头，表示此句与上下句的关系：
Consequently, I slowed down to avoid a fine ticket.
In fact, she was a kindhearted woman.
【同位语开头】
A signing officer of the bank, Jane signs her name hundreds of times each day at work.
A TV addict, Jim watches TV movies one after another every evening until after midnight.
【副词从句开头】
用副词从句开头，表示主句谓语动词发生的时间、地点、原因、方式、条件等：
