Did you notice that I used the 'future perfect' tense in the answer that I wrote for Thursday's writing task 1 lesson? Here's the sentence:
- By 2024, a third building will have been constructed.
In fact, this is a 'future perfect passive' sentence. Another option was to write:
- In 2024, a third building will be constructed. (simple future, passive)
There's a small difference in meaning between these two sentences. The future perfect sentence suggests that construction of the building will already be finished in 2024, whereas the simple future sentence suggests that the construction work will happen in the year 2024.