english grammer clause

She said (that) she'd collect it for me after work.

Yes, it is a noun clause, being the object of the verb "said".

It was so dark (that) I couldn't see anything. '

No, it is not an adjective clause but adverb clause, where "so that" is the subordinating conjunction to show an effect of the main clause.

Relative clause is another name for adjective clause. They are the same.

The man who [I saw yesterday] ate my lunch.
Yes, "who" can be omitted in the above sentence.

In the case of relative clause, the relative pronouns (which, who, whom, that) can be omitted when they are objects of verbs. When they are objects of prepositions, they can be omitted when they do not follow the preposition.

e.g. The man to whom I speak is a policeman.
The man (whom) I speak to is a policeman.

You reach a point in any project where you just want to get the thing finished.

"where" is a relative adverb in the above sentence. "when" is another relative adverb that can be used in a relative clause.

These are the principles which we all believe in.

Bingo! You got it right again. It is a relative pronoun introducing the relative clause to modify the noun "principles".





2011-08-06 08:02:12 補充：
"When" can be used in Relative Clause:
e.g. I will never forget the day when I graduated.

"When" can be a conjunction used in Adverb Clause:
e.g. When I was a little child, my parents used to take me to the park.

2011-08-06 15:17:01 補充：
It is a matter of basics.
"pronoun" replaces person or thing that was mentioned before.
"adverb" modifies verb, adjective or another adverb. It has adv of manner, adv of time (when), adv of place (where), ...

2011-08-06 15:21:19 補充：
The difference between relative pronoun and relative adverb is the same as that of pronoun and adverb. They both are used to introduce a relative clause (1) to replace person or thing (pronoun) or (2) to modifiy time or place (adverb).

2011-08-06 15:36:04 補充：
Direct speech and indirect (or reported) speech is a different topic. Don't mix them up!!

"that" is a pronoun when used in relative clause, but a conjunction when used in noun clause and adverb clause.
Reported speech has a structure of
subject + verb + object (noun clause).

2011-08-06 16:04:58 補充：
"where" can be adverb or conjunction, but not pronoun as it can't replace person or thing.

This is a city. I was born in this city. (in this city = adverb)
----> This is the city where I was born. (r. adverb) introduces relative clause

2011-08-06 16:08:02 補充：
You were also born in this city.
----> You were born where I was born. (conjunction) introduces adverb clause.

I first met you here. (here is adverb) I will meet him here as well.
----> I will meet him where I first met you. (conjunction) + adverb clause

你第一句並不是 relative clause ，而是 reported speech (陳述句) ，因為有那個 said ，在 reported speech ，said 後面是可加 that ，亦可不加。

第二句是 adjective clause

adjective clause = relative clause

是，who 是可以 omitted，可以 omit 的 relative pronoun 就只有 : who, whom, which, where, that。通常只要看見 relative pronoun 的後面是 noun，就是能omit relative pronoun。
E.g. This is the sweater which I bought on Saturday.
---> This is the sweater I bought on Saturday.

應該就這樣了(^^) 希望可以幫到你!