English grammar - Roger Berry 2012

B7.4 Phrasal-prepositional verbs
B7 Multi-word verbs
Section B Development

It is possible to have a combination of phrasal and prepositional verbs, where there is both a particle and a preposition:

Were looking forward to your party.

Forward is the particle, and to the preposition with the object noun phrase your party.

There may be an object separating the verb from the particle and preposition: Doctors have put his illness down to stress.