Isn't it wrong to say "dependent clauses can't stand alone"?

Question

Everyone says "dependent clauses are the ones that can't stand alone." I think that's a wrong interpretation of subordinate clauses. By that logic, even independent clauses can't stand alone. Let me explain:

"Rob went to the restaurant because he was hungry."

Of course, "because he was hungry" can't stand alone. But let's look a coordinating conjunction and do the same thing:

"Rob went to the jungle, and he got lost."

Can "and he got lost" stand alone? No. If you leave out the conjunctions, both sentences can stand alone.

So why do they say that?

In my opinion the difference is best put like this: coordinating conjunctions give more weight to one of the clauses, and that's why they are called "independent clauses". Subordinate conjunctions do the opposite.

Answer 1

A dependent clause is clause that is dependent on a larger clause, which is the matrix or main clause. Without the main clause, it cannot stand on its own. For example, "That he is right" is a dependent clause in "I agree that he is right".

However, not all elements that cannot stand on its own are dependent clauses. For example, "Singing a song" cannot stand on its own because it is a verb phrase; it needs a noun phrase subject to form a complete predicate.

There are many reasons why a string of words cannot stand on its on. It could be (1) it is not a constituent: "All of" cannot stand on its own in "I need all of the food" because "all of" does not form a constituent; (2) it needs a complement: "I put a book" cannot stand of its own because it needs an obligatory locative complement to specify where the book was put; or (3) it needs attached to larger clause such as the one you used as an example.

Incidentally, some grammars do not even consider "because he was hungry" as a clause at all. These grammars analyze "because" as a preposition. "Because he was hungry" is therefore a prepositional phrase.

Answer 2

With coordination of clauses, often the order of the clauses can be reversed, keeping the connective in between the two clauses:

• coordination of independent clauses
  • I'll have the chicken and she'll have the fish.
  • She'll have the fish and I'll have the chicken.
• coordination of subordinate clauses
  • Did you expect that I'd order the chicken or that she'd order the fish?
  • Did you expect that she'd order the fish or that I'd order the chicken?

This is usually not true of subordination:

• I predicted that she'd fall asleep.
• *She'd fall asleep that I predicted.

With because (described as a subordinating conjunction in traditional grammar), the clauses are also not reversible:

• Rob went inside because it was raining.
• It was raining because Rob went inside. [different meaning]

So I think the answer is best summed up as, coordination is different from head/dependent relationships such as independent/dependent clauses. Coordination may involve two main clauses or two subordinate clauses.