Hello Donnach,
It is almost magnificient
. I think that you will see now clearly what your analysis lacks to be perfectly magnificient.
Remember that mixing the levels of analysis is most often the cause of confusion.When you chop the whole sentence into pieces like we did ,splitting it into Subject - Verb - Direct Object (and for me ,this is the most important step in analysis,since the mistake in this initial step will make a mess in every further step) you may want to analyse
the Direct Object.The task was to analyse the structure of the direct object (..the red painted part in the sentence above - direct object..Would you please analyse the object of the sentence...),and you've labeled one part of it "the direct object".That makes confusion, so I would suggest you to always keep orientation in the analysis.Let's start from what I think is the confusing part:
1.This is the culprit :
...a built-in mechanism, which he called the Language Acquisition Device, or LAD, which pre-programs them to develop grammar based on the linguistic input they receive.
Although so lengthy ,
this is a noun phrase with 'mechanism' as its head.This noun head is pre-modified with the adjective "built-in" and postmodified with the two relative (adjective) clauses
2..Let's say that we substitute the second relative clause with "new" and say like :
..a new built-in mechanism which he called the Language Acquisition Device, or LAD
then you would make a mistake labeling the part "that children have a new built-in mechanism" as the direct object,this time leaving out the first relative clause as a postmodifier(you would never leave "new" out , I'm sure )
3..If we replace the first relative clause with "language" we have the noun phrase like:
...a new built-in language mechanism.
and in this case (without the relative clauses)you would label it right i.e "that children have a new built-in mechanism" is a direct object.
Remember this : Relative clause always postmodifies a noun or a noun phrase (and only marginally other clause).It is always embedded part of a noun phrase.In this case those two clauses postmodify the noun phrase "a built-in mechanism" or if you like it more,the noun "mechanism".The head of a noun phrase is(virtualy always): (if it is) premodified with an adjective or/and noun and (if it is) postmodified with a relative clause. A relative clause is not so straightforward modifier because of its length and the fact that it has its own subject and object. And that is why you left it out of the direct object.And it is labeled also as an adjective clause but personally I prefer "relative clause" for the sake of clarity in the terminology.As you see,in the third sentence the noun head "mechanism" is premodified with two adjectives (new, built-in),but also with the noun "language" and you will not label that noun i.e "adjectival noun".Similarly,"adjectival" doesn't seem apropriate label for the relative clause.This "relative" indicate that this clause relate to i.e refer back to some noun head.As a conclusion: a noun can be modified with an adjective, noun or a relative clause. The noun head along with its modifiers makes a noun phrase. I would like you to remember this also:
When you analyse sentence you first ask yourself what is it : "Is it a simple,compound or complex sentence.Then you ask yourself: "What functions is it consisted of."
Then you may want to analyse some functional part of that sentence(i.e subject,object..) and the first step is to ask yourself : "What is it by its form" i.e "Is it a clause,a phrase, or a word".
When you've identified what it is,follows the second step i.e ask yourself: "What functions is it consisted of."
And before.."The part I want to understand word for word",can you following this instruction say now:
1. What is the form of direct object?
2. What are the functional parts of it?
3. What is the form of every functional part respectively?
Leave out conjunction "that" and analyse it as a declarative sentence.
Best regards
Velimir