To give and receive are fundamental to the evolution of human relationships and business is no different. The language of negotiating plays a major role in constructing and maintaining relationships. We often use conditionals when negotiating and here is a quick guide to using just first and second conditional:
Example: If you give me a discount I will buy fifty units.
Example: If you gave me a discount I would buy fifty units.
So what exactly is the difference between the first and second conditionals? If you answered that the second happened in the past because it uses a past tense verb then I am sorry you are wrong. They are BOTH talking about the future.
The actual difference is to do with the speakers opinion. In the first sentence the speaker considers this a likely event that will happen, in the second sentence the speaker considers this less unlikely to happen. So there you have it, grammar can express your opinion as well as time periods.