What type of speech is master in the sentence advertisments promised instruction from a teacher?

The speech type in "advertisements promised instruction from a teacher" is passive voice.

Here's why:

* Active voice: The subject performs the action. Example: "The teacher promised instruction."

* Passive voice: The subject receives the action. Example: "Instruction was promised by the teacher."

In the original sentence, the subject is "advertisements," but they are not actually performing the action of promising. The action of promising is being done by an unknown entity (likely the creators of the advertisements). This makes the sentence passive.