Some people use “all together” and “altogether” interchangeably without having a clue that they are entirely different. “All together” and “Altogether” are adverbs, but in most cases, all together is also used as an adjective. Using these terms regularly in speech and writing helps to clear out all the confusion.
All together pertains to a group, it also means at the same time. On the other hand, altogether means total, overall, wholly, completely, etc.
When writing a text, one way to find out which one to use between all together and altogether is by taking the word "all" from the phrase and if the sentence makes sense, it means all together is the answer or otherwise.