When is the future perfect continuous used (explanation)?

The future perfect continuous tense (also called the future perfect progressive) is used to express actions or processes that will be completed at a specific time in the future. The critical fact in contrast to the future perfect simple is that the focus lies on the process itself and its duration:

• Some examples of how to use the future perfect progressive:
  • “We are so late. When we get there, she will have been waiting for two hours.”
    • process = will have been waiting
    • point in time = … get there
  • “By the end of the year, Thomas will have been working for this company for 30 years.”
    • process = will have been working
    • point in time = the end of the year

What is the rule for conjugating the future perfect continuous?

The form of the future perfect continuous includes the modal auxiliary verb ‘will’, the present perfect form of ‘to be’ (which is ‘have been’), and the word stem with added ‘-ing’ of the respective verb (which is the present participle). Note that this form does not change in any person and, therefore, ‘has’ is not used in the third person singular. Compare:

Conjugation rule of the future perfect continuous

Auxiliary verb ‘will’ + ‘have been’ + present participle (word stem + ‘-ing’)

Additional example sentences

• “I will have been talking to Mrs Anderson.”
• “Peter will have been drinking tea.”
• “The employees will have been eating in the factory canteen.”

Further explanations relating to the ‘Future perfect continuous/progressive’

The following explanations are related to the topic ‘Use of the continuous form of the future perfect tense’ and could also be interesting:

• Use of modal verbs in English
• Conjugation of ‘to be’ in the present tense
• Exercise 1: future perfect continuous/progressive