根據不同句型的構成原則，句子被分為兩類——鬆散句（loose sentence）和掉尾句（periodic sentence，又稱圓周句）。
鬆散句是指主要信息放在前麵，補充信息放在後麵的句子。笛福正是因使用鬆散句寫作而出名。他寫作時先以主要信息開頭，隨後補上一些相關信息。比如，在《魯濱孫漂流記》的故事開篇他寫道：
例32
I was born in the year 1632 in the city of York, of a good family, though not of that country, my father being a foreigner of Bremen, who settled first at Hull? he got a good estate by merchandise, and leaving off his trade lived afterward at York,from whence he had married my mother, whose relations were named Robinson,a very good family in the country and from I was called Robinson Kreutznaer?but by the usual corruption of words in England, we are now called, nay, we call ourselves, and write our name Crusoe, and so my companions always called me.
（1632年，我生在約克市一個上流社會的家庭。我們不是本地人。父親是德國不來梅市人。他移居英國後，先住在赫爾市，經商發家後就收了生意，最後搬到約克市定居，並在那兒娶了我母親。母親娘家姓魯濱孫，是當地的一家名門望族，因而給我取名叫魯濱孫·克羅伊茨內。由於英國人一讀“克羅伊茨內”這個德國姓，發音就走樣，結果大家就叫我們“克羅索”，以致連我們自己也這麽叫，這麽寫了。所以，我的朋友們都叫我克羅索。）
掉尾句則是指主要信息放在最後，相關介紹放在前麵的句子。這類句子經常以that、if、since、because等詞開頭。
例33
That through his own folly and lack of circumspection he should have been reduced to such circumstances as to be forced to become a beggar on the streets,soliciting alms from those who had formerly been the recipients of his bounty, was a sore humiliation.