Can someone please tell me what the difference is between the two phrases: Have not and Have never?
As far as I know, "have not" is usually used to mean that something has not happened in a period while "have never" means that it happened at no time in the past.
However, I am wondering if we can use "have never" when the time period we use is the entire period of an event.
A: Have you ever seen any beggars in this neighborhood? B: No, I have never seen one in this neighborhood in the past 25 years. (B has been living in this neighborhood for 25 years.)
Example 2 The defeat of Japan in 1945 was something the country had never experienced in the past 2500 years. (It's the length of the whole history of the country)
Example 3 The appearance of humans was something that had never happened on this planet in the previous three billion years.
However, when it comes to a period of time that is short or not the whole time span of an event, we should use "have not".
Example 4 A: Have you seen this guy in the past six months? B: No, I haven't seen anyone like this in the past six months.
Example 5 I have not played basketball for a month.
I have two questions here
Do I distinguish the two phrases correctly?
Can we ever use "ever" in a sentence that states a period of time: For example, can we change Example 4 to "A: Have you ever seen this guy in the past six months?" B: No, I have never seen this guy in the past six months"
Thanks in advance. Any advice is welcome!