when do you use present perfect?
When an action started in the past and continues into the present --
I have learned how to barbeque steaks.
(as opposed to "I learned how to barbeque steaks" -- a one-time action in the past)
http://grammar.ccc.commnet.edu/grammar/tenses/tense_frames.htm
To determine when to use the present perfect tense, you should consider the following situations:
1. Completed actions with a present effect: Use the present perfect when expressing an action that started in the past but has a connection to the present. This often includes experiences, accomplishments, or events that have relevance or consequences in the present. For example: "I have finished my homework," indicates that the homework is completed and has an impact on the present moment.
2. Unspecified time in the past: The present perfect is used when the time of the action is not explicitly mentioned or not important. It focuses on the result or outcome rather than specifying when it occurred. For example: "She has visited Paris," does not mention when she visited Paris, only that she has done it at some point in her life.
3. Past actions with a relevance to the present: Use the present perfect when discussing past events or actions that have a connection to the present moment or future actions. It emphasizes the continuous link between the past and present. For example: "I have lost my keys," suggests that the keys are missing now and may affect future actions like searching for them.
4. Recent past actions: The present perfect is used to describe actions that happened in the recent past. When expressing events that occurred just a short time ago, this tense is commonly used. For example: "I have just eaten dinner," indicates that dinner was consumed a short while ago.
5. Multiple actions over a period: Use the present perfect to discuss multiple actions or events that happened over a period up to the present moment. It emphasizes both the duration and the completed actions within that duration. For example: "She has written five books this year," highlights the fact that she has completed the action of writing five books within the time frame of this year.
Remember that the use of tenses may vary based on context and the specifics of the situation. These guidelines provide a general overview, but it's essential to consider other factors in determining the appropriate tense.