For example, it is acceptable in English to use sentences such as "I have not seen it" or "he has often said false things." (The auxiliary and main verbs are shown in boldface.) But that word order cannot normally be used in Spanish. These sentences must be expressed in Spanish as "no lo he visto" and "muchas veces ha dicho cosas equivocadas."
It is sometimes awkward in English to insert an adverb or other word between forms of "to be" and the gerund (the "-ing" form of the verb), but it is still done frequently. For example, "China is rapidly growing." But again, that word order normally isn't used in Spanish: "China está creciendo rápido."
Other than in works that have been poorly translated into Spanish, there are two instances where you're likely to see auxiliary and main verbs separated:
- Sometimes, a word or phrase can be inserted between a form of haber and a past participle to provide the sentence with a literary flavor. Example: No obstante, esta Corte ha, otra vez, rehusado a acogerse a esta propuesta. (Nevertheless, this court has, again, refused to invoke this proposal.)
- Pronouns can be attached to haber or habiendo. Example: Muchas personas dijeron haberlo visto vivo. (Many people reported having seen him alive.)

