Key Difference: The main difference between the two terms is that ‘all together’ means exactly what is says, everything (all) together. However, ‘altogether’ is used to indicate ‘wholly, to the full extent, or with everything considered.’ 

The first and the most obvious differentiation between ‘Altogether and All Together’ is that ‘all together’ are two different words that are clubbed together, whereas ‘altogether’ is one word and is used as such. While, ‘all together’ is used as two different words, which means that when used in a sentence, the sentence should work when they are separated from each other. For example: ‘they went there all together’ or ‘they all went there together.’ However, ‘altogether’ cannot be separated as it is one word.

Additionally, ‘altogether’ actually originates from ‘all together’. The word appeared as “altogeder, altogedere” in Middle English dating back to 1125. However, the first use of ‘altogether’ in Modern English dates back to 1893. In modern usage, the term has garnered additional meaning than the traditional “all together.”

The main difference between the two terms is that ‘all together’ means exactly what is says, everything (all) together. However, ‘altogether’ is used to indicate ‘wholly, to the full extent, or with everything considered.’  It indicates that to the full or entire extent, or to a complete degree. For example: I was altogether shocked. I was completely shocked, or I was really shocked. This indicates the extent to which I was shocked.

‘Altogether’ can also be used to indicate ‘on the whole’ or ‘with everything included.’ Foe example: Altogether, I had to pay $40 in fines. This means that after everything is considered, perhaps additional fees or taxes, the final amount in its entirety amounted to $40.

One way to differentiate between the two is to remember that ‘altogether’ can usually be exchanged with ‘completely’, whereas ‘all together’ cannot. Similarly, ‘all together’ can be separated from each other’s side and still mean that same thing, while ‘altogether’ cannot.

Additionally, note that ‘altogether’ has another meaning in the informal language, which means ‘in the buff’ or ‘in the nude.’

Comparison between Altogether and All Together:

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