One of the key components to learning English is to have an interactive environment. Children at this age learn from interacting with letters and words. For example, singing the alphabet song and holding up the letters will be more effective than reciting the alphabet for toddlers to hear. Showing kids the word apple and then letting them feel, smell and even eat an apple will help them learn the word more quickly.
The attention spans of young children are very short. An activity that drags on too long will result in kids becoming bored or distracted. The opportunity to teach them will pass quickly. Plan on several short activities for each block of study time when working with preschool children. Kids will not realize they've actually been studying for the past half hour if you use three different activities during that time period. Set up your activities in stations ahead of time. This will enable you to move the kids to the next station smoothly, while maintaining attention spans to absorb the material being taught.
Preschoolers enjoy the idea of playing. A world that is filled with different play activities will result in better learning. Use games that are fun and exciting to help kids learn. A great deal of language will be retained and children will have no idea they're being taught specific letters, words and concepts. You can have children paint letters, paint words, color pictures of letters, practice writing letters, act out scenes from story books, bring in items that begin with a specific letter or consonant sound to create learning opportunities.
Another key factor to learning English is parent involvement. Send home simple and short assignments that parents can do with their children on the weekends or evenings. This will reinforce the concepts, letters and words being taught in preschool. Children will have an opportunity to practice what they're learning. You can give parents games to play with the children or have parents help kids pick out items for show-and-tell. The more toddlers have a chance to practice what they learn at home, the better it will stay with them. Their English skills and vocabulary will quickly grow. For example, parents could be given written instructions of how to play a rhyming game with their toddlers. Or you could send home one sheet to color that has a letter of the alphabet with parental instructions on things to talk about while the child is coloring that particular letter.