Pada skill 9 kita mempelajari bahwa adjective clause connector can be use to introduce clauses that describe nouns,
Sementara pada skill 10, adjective clause connector tidak hanya sebagai connector: an adjective clause connector can also be the subject of the clause at the same time.
e.g.          
1)      we are looking at house that is quite expensive
                                                                                    ^{adjective clause}           
2)      the house that is quite expesive seems like a great house
                                               ^{adjective clause}

explanation:
In the first e.g. there are 2 clauses :
we is the subject of the verb are looking, and that is the subject of the verb is.   These two clauses are joined with the connector that.  The word that serves two functions at the same time : a)  The subject of the verb is; b) and It is the connector that joins the two clauses.
In the second e.g. there are 2 clauses:
House is the subject of the verb seems, and that is the subject of the verb is.   The word that serves two functions at the same time : a) It is the subject of the verb is, b) and It is the connector that joins the two clauses. 
Because, the quite expensive is an adjective clause describing the noun house, it directly follows house.

Apa saja yang termasuk dalam, adjective clause connector (subject) :

• Who (for people)
• Which (for things)
• That (for people & things)

Pattern :   S + V + adjective clause connector + V            OR

                   S  + adjective clause connector  + V + V

e.g. ___ just dropped off a package for you is my sister
        a.  the women
        b.  the women who
        c.  because the women
        d.  with the women

Additional explanation for adjective clause connector :

Adjective menjelaskan kata benda dan diletakan di depan kata benda tersebut;
Misal :   adjective + noun            →        big house
               She took my book         →        sebagai kata benda adalah she & my book
Kalau adjective biasa letaknya di depan kata benda, lain hal nya dengan adjective clause.  Bentuk nya akan berupa kalimat / clausa, dia akan mengikuti kata benda (noun) dan berada di belakangnya (bukan didepannya).

e.g.    i  remember the man who i killed yesterday
          S            P                          O                    adjective clause

Jadi adjective clause ini adalah akan menjelaskan noun (kata benda) baik berupa subject ataupun object dan letaknya akan berada di belakang noun yang akan dijelaskan.

Highlight :
1)  adjective claus bentuknya berupa kalimat (punya predikat)
2) menjelaskan noun daam sebuah kaimat (menjelaskan subject, object dan subject compliment)
3)  didahului : – Relative Pronoun (Who, Whom, Whoese, Which, That)
                          – Relative adverb (When, Where, Why)

Relative Pronoun
1)  Subject : Who, Which, That
      –   i talk to the woman. She is a doctor
          i  talk to the women who is a doctor         
             ^{S      P                        O                 adjective clause}
         –   i lost the book. It is a present from my boy friend. (it replaces the book)
           i   lost the book which is a present from my boy friend
               ^{S      P            O                                       adjective clause}
         –  the contract is no longer valid.  It was signed last year. (it replaces the contract)
          The contract that was signed last year is no longer valid
                          ^{S                             adjective clause} 
2)  Object : Whom, Which, That
      –   i meet the guy.  I accidentally hug him yesterday
          i meet the guy whom i accidentally hug yesterday.  (him replaced by whom)
      –  Chocolate is fattening. Many people adore it
         Chocolate which many people adore is fattening. (it replaced by which)
      –  the rat was in the kitchen.  Jhon saw it yesterday
          The rat that Jhon saw yesterday was in the kitchen. (it replaced by that)

Highlight :
–   bahwa relative pronoun yang menggantikan Subject
    Ciri-ciri : setelah relative pronoun pasti diikuti predikat (verb / aux)
–   bahwa relative pronoun yang menggantikan object
    Ciri-ciri : setelah relative pronoun pasti diikuti subject & predikat

3)  Possessive: Whose
Menggantikan kepunyaan baik berupa benda maupun orang.
      –   i built my own room.  It’s windows are very big
          i built my own room whose windows are very big
kalimat yang ke-2 menjelaskan windows dari my own rooms, berarti menjelaskan kepunyaan dari object kata benda.

      –   the woman was caught by the police.  Her son is a lawyer.
          the woman whose son is a lawyer was caught by the police.

Highlight :
bahwa saat penggunaan Relative Adverb (Where, When, Why) selalu           diikuti Subject dan kemudian Predikat (Verb / Aux)

Relative Adverb
Adapun connectors yang digunakan adalah :
– When      (adjective clause menjelaskan waktu)
– Where    (adjective clause menjelaskan tempat)
– Why        (adjective clause menjelaskan alasan)

e.g.     →   Banda Aceh is the city where i was born
                                                   ^{subj. supplement      adjective clause} 
           →   i can’t forget the day when we first met
           →   the reason why sarah didn’t want to go to school is her noisy friend

Highlight :

bahwa saat penggunaan relative adverb (where, when, why) selalu diikuti subject dan kemudian predikat (to be / verb)