连写句(run-on sentence、不断句/连续句/连缀句)是两个或更多的独立子句(independent clause、即"完整的句子")连接起来、而没有放置适当的标点符号或连词的句子。这这种句型普遍被认为是一种「文体的错误」，虽然它偶尔用在文学、或可作为一种修辞的技巧(rhetorical device)。连写句的例子是逗号拼接(comma splice)，其中，两个独立的子句直接使用逗号连接，而没有使用协调连词来配合。 有些规范文法(linguistic prescription)依据连写句的定义规范而排除逗号的拼接，但这并不意味着他们认为逗号拼接是可以接受的。

A run-on is a sentence in which two or more independent clauses (i.e. complete sentences) are joined without an appropriate punctuation or conjunction. For example:

Although this is generally considered a stylistic error, it is occasionally used in literature and may be used as a rhetorical device.