I have queries about past tense and present perfect tense.
I have made a appointment to see the university careers advisors immediately after the seminar,So I will need to leave on time.
I have done lots of presentations before and I feel OK about this one.
I got this two line from a grammar book. Now my doubt is Why we use present perfect tense instead of past tense in this two statements? I mean, both describe past activity.
After consulting various documents I got
Present Perfect vs. Simple Past
We must always use the Present perfect when the time of an action is not important or not specified.
We must always use the Simple past when details about the time or place that an action occured are given or requested.
One more thing
Can we use I have to leave on time instead of I will need to leave on time.