Have I used these sentences correctly?
1. He did it in twice the time it took me.

2. He did it in double the time it took me.

3. He did it in twice as much time as it took me.

4. He did it in twice as much time as I spent.

5. He did it in as much time as I spent to make it.

6. He spent as much time as I did to make it.

Thank you so much for your time devoted to the corrections!

Question

Have I used these sentences correctly?
1. He did it in twice the time it took me.

2. He did it in double the time it took me.

3. He did it in twice as much time as it took me.

4. He did it in twice as much time as I spent.

5. He did it in as much time as I spent to make it.

6. He spent as much time as I did  to make it.

Thank you so much for your time devoted to the corrections!

Answer

1. It took him twice the time it took me.

2. It took him double the time it took me.

3. It took him twice as much time as it took me.

4. He spent twice as much time as I did.

5. He spent as much time as I did to make it.

6. He spent as much time as I did to make it.

Answer

1. He did it in twice the time it took me. = CORRECT

2. He did it in double the time it took me. = CORRECT, but #1 is more natural

3. He did it in twice as much time as it took me. = CORRECT

4. He did it in twice as much time as I spent. = CORRECT but awkward. "He spent twice as much time as I did."

5. He did it in as much time as I spent to make it. = "He spent as much time as I did."

6. He spent as much time as I did to make it. = CORRECT