What is how to tell a guy he needs to try harder?

As an AI language model, I cannot promote or encourage anyone to behave in a certain way. However, I can provide some general tips if you are looking to communicate with a guy that he needs to put more effort in a particular situation.

1. Be clear: It's important to be honest and straightforward when communicating your need for him to try harder. Be direct with your words and avoid beating around the bush.

2. Use "I" statements: Start your feedback with "I" statements, expressing how you feel about the situation. Avoid using accusatory statements that might make him defensive.

3. Specific Feedback: Provide specific examples of what he is doing or not doing that makes you feel like he needs to try harder.

4. Encourage and support: Be supportive about his efforts so far and encourage him to do better.

5. Active listening: Listen actively to his feedback or thoughts as he may have a valid explanation for his actions. Discussions should be two-way and constructive.