What part of speech is the teaching?

The word "teaching" can be several parts of speech depending on how it's used in a sentence. Here are some examples:

Noun:

* The teaching of history is important. (Here, "teaching" refers to the act or process of teaching.)

* Her teachings were inspirational. (Here, "teachings" refers to the things that were taught.)

Gerund (verb acting as a noun):

* Teaching is a rewarding profession. (Here, "teaching" is the subject of the sentence and acts as a noun.)

* She enjoys teaching. (Here, "teaching" is the direct object of the verb "enjoys" and acts as a noun.)

Present participle (verb form acting as an adjective):

* She gave a teaching speech. (Here, "teaching" modifies the noun "speech" and describes the type of speech.)

So, without context, it's impossible to say definitively what part of speech "teaching" is. You need to look at the sentence it's used in to determine its function.