Causative constructions
When one does not carry out an action oneself but rather has the action done by someone else, this is expressed by a causative construction. In English it is the verb "to have" that introduces the causative. The model will generally be: "to have" (conjugated) + direct object (noun or pronoun) + principal verb (in its past participle form):
When one wishes to designate the agent of the action (the person who has carried out the described action), there are two possibilities:
1. -- "to have" (conjugated) + direct object (noun or pronoun) + principal verb (in its past participle form) + "by" + agent (usually not as a pronoun):
2. -- "to have" (conjugated) + agent (as a direct object noun or pronoun) + principal verb (in its infinitive form) + the object (also in the form of a direct object noun or pronoun)
Note: Especially in spoken English, the verb "to get" often replaces "to have," in which case "to" is added to the infinitive (but not before past participles). This construction also suggests that it may be (or have been) difficult to produce a certain reaction on the part of the agent:
When one wishes to express a change in temperament or in general conditions, it is the construction "to make + adjective" which is used: