All together and altogether look similar, but they do different jobs.
All together usually means everyone or everything in one place, at one time, or acting as a group. If you can replace it with everyone together or everything together, this is probably the right choice.
Example: We stood all together for the photo.
Altogether usually means completely, entirely, or on the whole. It often describes the degree of something or gives a general summary.
Example: The second draft was altogether clearer.
A helpful test is this: if you are talking about a group, use all together. If you mean completely or overall, use altogether.
- They worked all together to finish the project.
- The delay was altogether unexpected.
- The trip was altogether worth it.
This pair can be confusing because the words look nearly identical. Focus on meaning, not just spelling. One points to a group acting in unity, and the other points to totality or general judgment.