Learn Farsi: جهان در شرف یک انقلاب علمی است. - The world is on the verge of a scientific revolution.

The phrase dar shorof requires an Ezafe to link it to the noun phrase that follows. Even though it is not written, you must pronounce it as dar shorof-e, attaching the invisible Ezafe to the final letter of shorof right before saying the word yek.

The lesson also mentions dar âstâne-ye. Could we swap it into this sentence?

Absolutely. You could say jahân dar âstâne-ye yek enghelâb-e elmi ast. Both phrases are formal, mean on the verge of or on the threshold of, and both connect to the following noun phrase using an Ezafe.

How is the adjective elmi (scientific) formed here?

It is formed by taking the noun elm (science or knowledge) and adding the suffix -i to turn it into a descriptive adjective. It then connects to the noun enghelâb (revolution) with a standard Ezafe, pronounced as enghelâb-e elmi.

This sentence places a noun phrase after dar shorof-e. What if we wanted to describe an action instead, like on the verge of changing?

To use a verb after expressions of imminence, you use the long infinitive, which is the standard dictionary form of the verb ending in -tan or -dan. For example, on the verge of changing would be dar shorof-e taghyir kardan.