Categorize the following words under the correct parts of speech.
- Quick
- Explained
- Constantly
- Quick: Adjective 
- Explained: Verb 
- Constantly: Adverb
Complete the following task based on the instruction and optional input provided.### Instruction:
Categorize the following words under the correct parts of speech.

### Input:
- Quick
- Explained
- Constantly

### Output:
- Quick: Adjective 
- Explained: Verb 
- Constantly: Adverb