A COBOL statement is always introduced by a reserved word called a verb. A verb and its operands describe some action to be taken when the program runs. A sentence is one or more statements that are terminated by a period.
There are four types of statements:
An imperative sentence is one that contains only imperative and delimited-scope statements. A conditional sentence consists of a single conditional statement optionally preceded by a sequence of imperative statements.
Several verbs can be either imperative, conditional, or delimited-scope. For example, a simple READ statement is imperative. If the AT END clause is included, it becomes conditional. On the other hand, if the END-READ phrase is also included, then it is a delimited-scope statement.