 Now let's take a look at the future perfect continuous tense. This tense is used to talk about how long an action had been taking place up until a certain point in the future. Our examples are for the positive sentence we have our subject u and three auxiliary verbs will have been and then our main verb in the present participle form again that's the verb plus ing. For our negative form again we're simply inserting the word not between will and have and to ask our question we invert will with the subject here we're using you and we come up with a question will you have been watching and the rest of our sentence. As with the other future tenses the word will can be substituted for other modal verbs these modal verbs would indicate varying levels of certainty for the future so again we could substitute may or might for the word will. Also with the future tenses the will and not will contract into its contracted form of won't. As mentioned earlier the usage for the future perfect continuous tense is to show how long an action will have happened by a future time. Our example sentence reads by the end of this year I'll have been living in London for 20 years so I'm talking about a point in the future by the end of this year and how long the action will have been happening by that time. By the end of this year I'll have been living in London for 20 years. A teaching idea for the future perfect continuous tense includes a survey. Here we want to be able to find out the duration of an activity at a certain point in time for the future. A sample question might be how long will you have been learning English for by the end of the year. At the end of the activity we should be able to identify who will have been learning English for the longest and who will have been learning English for the shortest amount of time.