Preschoolers between 3 and 5 years love to learn.  They also love to talk about what they have learned.

It's a magical time of growth in language and refining speech clarity.  Preschoolers learn more concepts and as a result, sentences get much longer. Social skills become more sophisticated and preschoolers start to express their emotions.

At three, expect your preschooler to understand and start speaking about concepts 

• pronouns (he, she, his, her)  
• rote counting and quantity (I have three cookies.)  
• a few colours
• negation (It's not a bear.)
• follow simple stories
• category words (clothing, animals, food)
• answer simple questions of who, what, where
• improve articulation of sounds to about 80% accuracy 

 At four, expect your preschooler to understand and start speaking about concepts 

• location concepts (beside, behind, in front of)
• time concepts (later, this morning, this afternoon, at night)
• shapes (circle, square, triangle)
• follow 3-4 details in a sentence
• answer WH questions, who, what, where, when
• adjectives (The hamster has little ears.) 
• past tense (The ice-cream melted.)

At five, expect your preschooler to understand and start speaking about concepts 

• finer body parts (ankle, elbow, forehead, eyelashes)
• written forms of language ("Ryan" that's how you spell my brother's name.)
• tell a story in sequence
• count to 10 and gives the correct number (I need five stones.)
• correct absurdities (That's not right. A hat doesn't go on my foot.)