1. This is the way he did it.
2. This is how he did it.
3. This is the way in which he did it.
4. This is the way by which he did it.
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Are they all grammatical? Can we use 'by' instead of 'in'?
2. This is how he did it.
3. This is the way in which he did it.
4. This is the way by which he did it.
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Are they all grammatical? Can we use 'by' instead of 'in'?