<prompt> Translate the following text to EnglishSheria ya uhamiaji ya Marekani inaruhusu wenzi wa ndoa wa raia wa Marekani kuwa raia wa Marekani, na ni tofauti chache tu, kama vile ndoa za uwongo zilizofanywa kwa kusudi la kupata uraia.  <response>: U.S. immigration law permits spouses of American citizens to become American citizens with only a few exceptions, such as sham marriages undertaken for the purpose of obtaining citizenship. 