1. In an hour, we arrived at the base.
2. After an hour, we arrived at the base.
3. In an hour, we will arrive at the base.
4. After an hour, we will arrive at the base.
(Which preposition do we have to use? Which ones are correct?)
2 answers
They are all correct. However, 1 is unclear, depending upon the preceding sentence.
2 and 3