Since a few years ago, the British Government has applied the requirement for everyone applying for some certain UK visas to pass an English test. One of the English tests is the B1 English test. You can take this test in several certain institutions. You can see the list of the institutions on http://britishlifeskills.com.
B1 English test is the particular English test that those who are applying for a spouse visa. To be able to pass this test, you certainly need to have your English skills equal to the B1 level. It means that you need to be able to speak English at the intermediate level. You have to prove to that you can speak English with good grammar that other people will be able to understand what you speak. Other than that, you are also required to have a good listening skill so that you will understand other people as well. So, by having those skills, the chance of you to pass the test will be better.