“的确”和“确实”都可表示完全属实。但“的确”是副词，只能做状语。“确实”可以做多种句子成分。两个词均可以重叠。做状语时，一般可换用。
的确 and 确实 both mean “absolutely true.” But 的确 is an adverb and can only be an adverbial. 确实 can be used as quite a few sentence elements. Both words can be reduplicated. As an adverbial, they are interchangeable.
(1)我当时的确（确实）在场。
（2）他确确实实（的的确确）已经结婚了。

“确实”做其他成分时，不能和“的确”互换。
When 确实 functions as other sentence elements, 的确cannot replace it .
(3)这条新闻不确实。
（4）请告诉我你的确实位置。