constituency tests (idea)

If you're charting sentences (whether in class or the Serengeti), there are several common tests for linguistic constituency. We'll apply them first to a phrase -- "the store" -- in a simple sentence: The very young child walked from school to the store.

1. Substitution Replace the phrase in question with a single word that preserves its general meaning. In this case, it works well: The very young child walked from school to it.
2. Movement Transfer the phrase somewhere else (to the beginning of the sentence, usually) and add a pause. The store, the very young child walked from school to. This doesn't work so well, but that doesn't mean "the store" isn't a constituent. We're looking for evidence, not proof or disproof: presumably, there's a syntactical reason the test failed in this instance (perhaps the proscriptive rule never to end a sentence with a preposition has some merit after all). A slight modification works better. The store, the very young child walked from school to it. It's not proscriptively grammatical, but it's certainly idiomatic.
3. Coordination Add a parallel phrase. The very young child walked from school to the store and the park. Ching!
4. it-clefts Without going into the ghastly details, rearrange the sentence thusly: It's the store that the very young child walked from school to. A bit ungaily, but it works.
5. Question and Answer Snip the phrase from its sentence and sculpt the former into a question. Where did the very young child walk from school to? The store.

A second example, and a less straightforward one: The small clause "from school to the store".

1. Substitution Nope. But that's because English simply doesn't have a word that substitutes for this particular syntactic structure.
2. Movement From school to the store the very young child walked.
3. Coordination The very young child walked from school to the store and from the store to the house.
4. it-clefts It's from school to the store that the very young child walked.
5. Question and Answer Where did the very young child walk? From school to the store.

One more valid one, tougher still. "Very young," an adjectival phrase.

1. Substitution
2. Movement Very young, the child walked from school to the store. This doesn't actually work (in English, noun phrase constituents can't break out): compare The circus elephants and very young children walked from school to the store and Very young, the circus elephants and children walked from school to the store and you'll see the structure has changed.
3. Coordination The very young and irredeemably ugly child walked from school to the store.
4. it-clefts It was very young that the child walked from school to the store. Nope. You could modify this to It was very youngly that the child walked from school to the store but young would then be modifying just walking rather than most of the sentence.
5. Question and Answer Which child walked from school to the store? Very young. Something a very young child might say, perhaps, but not adult English grammar.

Finally, a non-constituent: "child walked"

1. Substitution Nothing.
2. Movement The very young from school to the store child walked. I don't think that would even work in Latin.
3. Coordination The very young child walked and spaceship flew from school to the store. Violates rules against nonparallel structure. (So claims my ling teacher, though it doesn't sound so bad to me.)
4. it-clefts It was child walked that the very young from school to the store. Heh.
5. Question and Answer Which the very young from school to the store? Child walked.

The solutions aren't always transparent, but the tests can help. Node your homework.