Page "Phrasal verb" Paragraph 67

The two categories have different values.

Particle-verb compounds in English are of ancient development, and are common to all Germanic languages, as well as to Indo-European languages in general.

Those such as onset tend to retain older uses of the particles ; in Old English on / an had a wider domain, which included areas which are now covered by at and in in English.

Some such compound nouns have a corresponding phrasal verb but some do not, partly because of historical developments.

The modern English verb + particle complex set on exists, but it means " start to attack " ( set itself means start a process ).

In modern English there is no exact verbal phrase equivalent to the older set on, but rather various combinations which give different nuances to the idea of starting a process, such as winter has set in, set off on a journey, set up the stand, set out on a day trip, etc.

Verb-particle compounds are a more modern development in English, and focus more on the action expressed by the compound ; that is to say, they are more overtly " verbal ".