The more words you know, the more you understand.

The research

Vocabulary size is strongly associated with reading, listening and writing ability.

• No magic threshold. Every word counts.

  Schmitt, Jiang & Grabe (2011) tested 661 learners across 8 countries and found a linear relationship between vocabulary size and text comprehension.

• r = .65

  Vocabulary knowledge tracks listening comprehension closely.

  Ha (2021) measured the vocabulary knowledge and listening comprehension of 234 English learners and found the two correlated at .65 — calling receptive vocabulary a powerful and reliable predictor.

• 2,000words

  The level worth aiming at first.

  Across 88 learners, Stæhr (2008) found vocabulary size strongly associated with reading and writing ability, and concluded that the most frequent 2,000 words are a crucial learning goal for lower-level learners.