so much so that vs. so that

Example 64

[64] The Coo-ee cordial factory prospered almost at once, so much so that my father bought a new house at Coorparoo.

In the sentence above the word so is taking the place of a clause. If we reinsert the clause in place of so, it will read:

The Coo-ee cordial factory prospered almost at once, so much did the Coo-ee cordial factory prosper that my father bought a new house at Coorparoo.

[Notice here that the clause following that is not related to the so that we replaced. It is a dependent of the initial degree adverb so at the very beginning of the clause. The sentence is similar in structure to:

• So fast did it go that we could not catch it.]

Example 72

There had been a power failure, so that all classes had had to be cancelled.

Here the word so does not represent a clause. In fact it is appearing between two clauses:

• [There had been a power failure] so [that all classes had had to be cancelled.]

The word so here belongs with the second subordinate clause, of which it is the head. This so is different from the one in (64). In (64), the pro-clause so was not related to the clause following it. We showed that, in fact, the clause following so in that construction is actually a dependent of the earlier degree adverb so. However here, in example (74), the following clause is directly related to the word so. This is because the word so tells us that the classes being cancelled is a result of what was described in the main clause.

The so in (74), therefore, is a very different beast from the one in (64). Nonetheless, it still has some similarities. Apart from sounding the same, both have an anaphoric relationship with what has been said before. However, in (74), the word so is not a pronoun, pro-verb, or pro-clause. It is merely a resultative preposition.

The key to understanding so that and so much so that lies in grasping how many roles "so" can actually play, and identifying which role(s) it plays in the expressions you are considering.

In the Wiktionary entry, there's an etymology drawing on multiple European languages. However, there's also parallel usage in French (tel, tellement) and the sound itself occurs in other languages that have influenced English in other ways, such as Japanese.

The general usage of so is to refer to something that has already been established between two speakers, or between the writer and the reader, as in Jean-Luc Picard's well-known "Make it so" from Star Trek.

In the Wiktionary entry, so is first characterized as a conjunction and as an adverb, but examples of its other uses are given later.

The key to identifying the role of any given so is to transform the expression by replacing so with a more specific word or set of words that convey the same meaning. For example:

• so = "I accept what you just said, and the consequence will be what you say next." Essentially a conjunction, like therefore. If you can replace the so with therefore, you have narrowed down its role. It can be a conjunction uniting two related but independent actions, or the introductory word in an adverbial clause, which modifies the first action (the Wiktionary gives therefore as an adverb).

• so that is almost the same as so, since in most English expressions that can be eliminated without changing the meaning. In practice, however, so that connotes purpose. Compare:

  • The air cooled, so the leaves changed color. Conjunction. Replacing so with and does not change the meaning (very much).

  • The farmer placed nets below the trees, so that the apples would be caught before they reached the ground. Adverb identifying the goal of the first action. Replacing so with and changes the meaning by de-emphasizing the will of the farmer. Replacing so with in order that or with the purpose of keeps the meaning intact.

• so much so that: an expression that introduces an adverbial clause by referring to two previously expressed ideas. It's probably best to view this as an idiom that allows you to make these references conveniently. For example: in The Coo-ee cordial factory prospered almost at once, so much so that my father bought a new house at Coorparoo, we have:

  • the first so refers to the verb prospered, but it plays a double role as an adverb for the so that follows. You could replace so much so that with so remarkably that and keep the meaning.

  • the second so refers to the adverbial phrase almost at once. You could replace it with better than his competitors and still have a meaningful statement.

  • much is functioning as an adverb modifying the second so. You could replace it with ridiculously, i.e. ...prospered almost at once, so ridiculously so that my father bought...

As a further example, we could imagine a Jean-Luc Picard saying: "Make it so. So much so that these creatures never return to this part of the Galaxy again."

So the challenge with identifying so as a part of speech is that the prior reference is sometimes hard to infer. So perhaps it's best to think of expressions with so as special cases of conjunctive propositions introducing adverbial clauses.

Finally, don't forget that CGEL offers a somewhat narrow academic perspective on our language, and that there's actually quite a lot you can say with so, e.g.

• Alphonse: And so?

• Gaston: So, since you so want to know, Miss So-and-so lives in that so-so district that we keep hearing so much about. So just let it be, okay?"

• Alphonse: Oooh... soooo intense. So tell me how come, huh?