# Difference between “so dass” and “sodass”?

I’m having trouble finding the difference between so dass and sodass. Do they mean the same thing, like mithilfe and mit Hilfe, but are just spelled differently, or do they have different meanings? For instance:

Sprechen Sie laut und deutlich so, dass jeder Sie versteht.
Sprechen Sie laut und deutlich, sodass jeder Sie versteht.

The Duden states that so dass is an alternate spelling of sodass, and gives an example sentence where the two words are interchangeable. But when I turned in a math assignment to a (German) math professor, I was told that sodass was wrong in the following (simplified) example:

Es existiert ein a, sodass 2a =x.

This makes things even more confusing.

• This usage of "so dass," which is specific to mathematics, more or less, was discussed in german.stackexchange.com/questions/30013/…. It differs in meaning or intent from the usages discussed by Wrzlprmft. I won't elaborate much, as the answers from above are better than what I could write. I will only say that "such that" or "so dass" often occurs in a specific logical construction "there exists an a, such that something happens involving a". The "such that" here has the meaning "with the property that" rather than "with the result that". Oct 9, 2017 at 22:23
• On the different usage in mathematics see german.stackexchange.com/questions/30013/… Oct 10, 2017 at 6:15

Let’s start off with the three following simple examples:

Er betätigte zwei Tasten, sodass der Alarm ausgelöst wurde.
Er betätigte zwei Tasten so, dass der Alarm ausgelöste wurde.
Er betätigte zwei Tasten, so, dass der Alarm ausgelöste wurde.

In the first example, him pressing two keys causes the alarm; it does not matter which keys he pressed or how. In the second example, he needs to have pressed two particular keys or pressed them in a particular way for the alarm to go off. The third example is like the second one, but everything following the first comma is used parenthetically or after a break of thought – the first comma could as well have been a dash (Gedankenstrich). Note that those three cases are differentiated in spoken language by pauses at each comma.

Now, let’s look at your examples:

Sprechen Sie laut und deutlich, sodass jeder Sie versteht.
Sprechen Sie laut und deutlich so, dass jeder Sie versteht.

In the first case, speaking loud and clearly is supposed to cause everybody to understand you. In the second case, you are instructed to speak loud and clearly in such a way that everybody understands you. The example is however rather unidiomatic and I would rather say:

Sprechen Sie laut, deutlich und so, dass jeder Sie versteht.
Sprechen Sie laut und deutlich, und zwar so, dass jeder Sie versteht.

Your second example is actually correct the way you did it, as the following would imply that a given a can exist in many different ways and only in some of them, 2a would be x:

Es existiert ein a so, dass 2a =x.

While the above is all correct and rather simple, things are made complicate in two ways:

• According to § 74 E1 of the spelling rules, the second comma in the third variant of the first example is optional, so you can also write:

Er betätigte zwei Tasten, so dass der Alarm ausgelöste wurde.

• § 39 E3 (2) of the spelling rules is explicitly allows writing so dass instead of sodass. I personally advise against this because it can be confused with the above and, going by stress and pauses, nobody speaks sodass as two words anymore – at least in my experience. When copy editing, I always change so dass to sodass. The Duden dictionary also lists sodass as preferable spelling. According to the old German spelling (prior to 1996/2006), only so dass was valid and some people may not have noticed that this has changed (or are stubborn) and thus state incorrectly that sodass is wrong.

• After a lengthy and friendly chat I would just like to point out that the professor's objection may have been that „Es existiert ein a, sodass 2a=x“ could be read as “There exists an a. Therefore, 2a=x”, which certainly was not intended. Still, mathematicians certainly do not say „ein a so, dass“, and if grammar rules do not differentiate between „..., so dass“ and „..., sodass“, then a maths professor is probably well advised not to insist on such a difference. Jan 14, 2015 at 22:24