Relative Adverbs

Whereas interrogative adverbs are used at the beginning of a sentence to form a question, relative adverbs are used in the middle of a sentence to separate clauses. The relative adverbs are where, when, and why. They are used to introduce the second clause which is relative to the first. 

Examples:

• That’s the classroom where I learned English.
• Do you want to know why English grammar is so difficult? 
• Doing arts and crafts reminds me of a time when life was so simple.