As an adjective describing a plan or arrangement:
* "We have a tentative date for the wedding, but it's subject to change."
* "The company announced a tentative agreement with its employees, but further negotiations are planned."
* "Due to the weather, our hiking plans are tentative."
As an adjective describing a feeling or belief:
* "I feel tentative about starting my new job, but also excited."
* "She offered a tentative smile, unsure of how to respond."
* "He had a tentative belief that he could win the race."
As an adverb describing an action:
* "He tentatively reached out to touch her hand."
* "She tentatively agreed to go out to dinner with him."
* "The child tentatively took a bite of the unfamiliar food."
Remember that "tentative" implies something is not definite or firm, and may be subject to change.