1. Fold the paper in half.
2. Fold the paper in two.
3. Fold the paper into three pieces.
(Are all grammatical? Do we have to use 'in' or 'into' in this case?)
1 and 2 are fine.
3 should read, "Fold the paper in thirds."
2. Fold the paper in two.
3. Fold the paper into three pieces.
(Are all grammatical? Do we have to use 'in' or 'into' in this case?)
3 should read, "Fold the paper in thirds."