Federal law requires immigrants to "demonstrate an understanding of the English language, including an ability to read, write, and speak words in ordinary usage" to become a U.S. citizen. However, the law has exceptions for people with disabilities and those who are over certain ages and have lawfully resided in the U.S. for certain lengths of time. Also, the Inspector General of the U.S. Department of Justice found that the Clinton administration "did not properly enforce the English-language requirement" when awarding citizenship to immigrants. Because communication is essential to productivity, a failure to learn English limits earning power and makes people more reliant on welfare. Recent immigrants have made significantly less progress in learning to speak English and increasing their incomes than earlier generations of immigrants.