jest – how to check if a word is a english word

I am using Jest to test for a function, which generate a english word.

I tried below but not working. Just want to check if the word is combined by english characters

  it("generate a english word", () => {
    const word = "APPLE";
    expect(word).toMatch('/^[A-Za-z]*$/');
  });

What’s wrong with it?