Questions & Answers about از آن دیوار بلند نپرید.
How exactly is the negative command نپرید (do not jump) built?
It is made by taking the present stem of the verb پریدن (to jump), which is پر (par). We add the negative command prefix نـ (na-) to the front, and the plural or formal "you" ending ـید (-id) to the end. This gives us na- + par + -id = naparid.
Is this sentence addressing one person or multiple people?
The verb ending ـید (-id) in نپرید means it is addressed to either a group of people ("you all") or politely to one person (formal "you"). To tell just one person informally not to jump, you would drop the ending and just say نپر (napar).
Where is the invisible connecting sound (ezafe) in this sentence?
There is an ezafe connecting the noun دیوار (wall) and its adjective بلند (high). Even though it is not written, you must pronounce it as divar-e boland.
Why doesn't the word آن (that) need an ezafe to connect to دیوار (wall)?
Demonstrative words like این (this) and آن (that) are exceptions to the usual rule. They always come before the noun they describe and they never use an ezafe to connect to it. You just say ān divar.