An adjective clause describes a noun. Because the clause is an adjective, it is positioned directly after the noun that it describes.
Bahwa adjective atau kata sifat menjelaskan kata benda dan terletak di depan (sebelum) kata benda tersebut.  Mis. adj + noun → big house
Namun sebuah adjective clause bentuknya berupa sebuah kalimat / klausa dimana adjective tersebut akan mengikuti (setelah) kata benda dan bukan di depan kata benda.

Contoh kalimat : i remember the man who i killed yesterday.
subject       : i
predicate   : remember
object         : the man
adj clause : who i killed yesterday

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.

e.g.          
1)   this is the house that i want to buy
                                                        ^{adjective clause}
2)   the house that i want to buy quite expensive
                                         ^{adjective clause}

explanation:
In the first e.g. there are 2 clauses :
this is the subject of the verb is, and i is the subject of the verb want.  That is the adjective clause connector that join these two clauses, and the adjective clause that i want to buy describe the noun house.
In the second e.g. there are 2 clauses:
House is the subject of the verb is, and i is the subject of the verb want.   That is the adjective clause connector that join these two clauses, and the adjective clause that i want to buy describe the noun house 

Apa saja yang termasuk dalam, adjective clause connector :

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

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

                   S  + adjective clause connector + S + V + V

e.g.  The job ___ started yesterday was rather difficult
         a. when
         b. was
         c. after
         d. that he