The future perfect tense is used to talk about actions that will be completed at a specific point in the future. It emphasizes the completion of an action rather than the duration.

 Structure
The structure of the future perfect tense is:

Subject + will have + past participle (verb in the third form)

 Usage
1. To indicate an action that will be completed before a certain future time or event  
   This tense is often used to talk about an action that will have finished by a specific time or before another action in the future.

   - Example: By next month, she will have completed her project.
     - (This means she will finish her project sometime between now and next month.)

2. To describe something as already finished before a specified time in the future  
   It expresses certainty that an action will be completed by a particular future moment.

   - Example: They will have left by the time you arrive.
     - (This means they will be gone before you arrive.)

 Examples
- I will have finished my homework by the time you get home.
- By tomorrow, we will have cleaned the entire house.
- They will have graduated by June.

 Time Expressions Often Used
Common time expressions with the future perfect tense include:
- by + a specific time: by tomorrow, by next year, by 6 p.m.
- by the time + another future event: by the time you arrive, by the time she comes back

 Key Points
- Focuses on the completion of an action before a specific point in the future.
- Requires the auxiliary verbs will have followed by a past participle.

The future perfect tense is helpful for discussing goals, deadlines, or planned completions that are set to be achieved by a future moment.