Adjective clauses are phrases that can identify or describe a thing, place or person. They are a phrase that comes after a noun. They tell us more about that noun. For example:

"the person who lives next door"; or
"the time that we went to Disneyland".

To review, read the introduction to adjective clauses. You should also read about the two main types of adjective clause.

When you can drop joining words

Remember that we use a joining word to connect a noun to the adjective phrase:

1. "the place where James was born";
2. "the people that we met on vacation";
3. "the souvenirs which Ben and Claire bought". 

These joining words can be left out. We sometimes cut the joining words in spoken English and in informal writing:

1. "the place James was born";
2. "the people we met on vacation";
3. "the souvenirs Ben and Claire bought".

This is not always possible.

To understand this next point, you need to know about identifying and describing adjective clauses. Let's review quickly:

1. A "describing clause" tells us more about something or someone;
2. An "identifying clause" identifies something or someone.

A describing clause is not needed in a sentence (the information it gives us is a nice bonus), but an identifying clause is important and cannot be cut from the sentence:

1. Naoto likes to watch True Blood, which is a show about vampires. 
2. What is the name of the TV show that you like?

We use identifying clauses when we want to be more specific. Often it is because we don't know the name of something or someone (like in the example above where we want to know the name of the TV show). We use a describing clause when we want to be more helpful. The information in the describing clause is an extra thought.

You can only leave the joining words out of an identifying clause (type 2 above), if there is a subject in the clause. You must use the joining word when you use a describing clause. Here are some examples: