 And now we'll have a look at the present perfect continuous tense. As its name suggests, what we're going to do is combine the present continuous usages and the present perfect usages into a tense that basically expresses the fact that we've got an action continuing up until the present point in time. For the form of this tense, again we're going to combine the various aspects of both the perfect and the continuous tenses. If we have a look, we always begin with our subjects. Then we have our two now helping verbs, the helping verb to have for the perfect tenses, as well as the helping verb to be for the continuous tenses. For our subjects I, you, we, and they, we leave have as have. For he, she, and it, we conjugate it to has. Because it's a continuous tense, of course we need to use the verb plus ing. This results in sentences such as I have been teaching quite some time, or she has been teaching for 15 years. The negative form of the present perfect continuous remains the same as the positive form, and we simply add not in between our two helping verbs have and be.