Enhancing the vocabulary of primary English students is pivotal for their language development, improving their communicative competence, reading comprehension, and writing skills. It also paves the way for success in examinations, such as the PSLE English Composition, and beyond. Here’s a thorough discussion on how to increase vocabulary in primary English students:

1. Creating a Reading Culture: A love for reading can be one of the most potent tools for vocabulary expansion. Encourage students to read widely and diversely, covering various genres such as fiction, non-fiction, poetry, newspapers, and magazines. With exposure to different contexts and styles of writing, students naturally absorb new words, phrases, and language structures.
2. Word of the Day: Implementing a ‘word of the day’ routine can make vocabulary learning a fun, daily activity. Choose an interesting word each day and discuss its meaning, pronunciation, usage, synonyms, and antonyms. Encourage students to use the word in their oral and written communication throughout the day.
3. Interactive Vocabulary Games: Games can make learning an enjoyable experience. Crossword puzzles, word searches, scrabble, Pictionary, and online vocabulary games can help students learn new words in a fun, engaging, and memorable way.
4. Explicit Vocabulary Instruction: While implicit learning through reading and exposure is crucial, explicit vocabulary instruction is equally important. Teach students new words directly, explaining their meanings, usage, and context. Make use of visual aids, examples, and mnemonic devices to aid understanding and retention.
5. Word Lists and Flashcards: Word lists and flashcards can be effective tools for learning new words. Organize them by themes, categories, or levels of difficulty. Review these cards regularly to reinforce learning and improve long-term retention.
6. Encouraging Word Usage: Encourage students to use new words in their oral and written communication. This active usage not only helps in better retention of the words but also aids in understanding the nuances of their usage.
7. Exploring Word Roots, Prefixes, and Suffixes: Teaching students about word roots, prefixes, and suffixes can empower them to deduce the meanings of unfamiliar words, expanding their vocabulary indirectly.
8. Keeping a Vocabulary Notebook: A vocabulary notebook, where students can jot down new words they encounter along with their meanings, synonyms, antonyms, and sentences, can serve as a personal, growing dictionary, aiding review and reinforcement.
9. Literacy-Rich Environment: Creating a literacy-rich environment, where students are surrounded by books, word posters, and other reading materials, can subconsciously enhance their vocabulary.
10. Regular Assessments and Reviews: Regular vocabulary tests and reviews can reinforce learning and ensure the newly learned words are not forgotten. It also helps in tracking progress and identifying areas for improvement.

Remember, the goal is to enhance students’ vocabulary in a way that’s enjoyable and sustainable. It should be a continuous process, nurturing a lifelong love for words and language. Keep the process interactive, engaging, and aligned with the students’ interests and level of understanding. This approach will not only increase their vocabulary but also boost their confidence, creativity, and overall language proficiency.