Muslim women who fail to improve their English language skills could be deported as part of a drive to build community integration and counter extremism, David Cameron has said.
The Prime Minister warned that not speaking the language adequately could make people "more susceptible" to the recruitment messages of groups like the self-styled Islamic State (IS) - though there was no "causal link".
And he said it was "not acceptable" that women in parts of the UK were not allowed to leave their homes without a male relative and faced sex-segregated school governors meetings.
A £20 million language fund is being set up to help end what he called the "passive tolerance" of separate communities which left many Muslim women facing discrimination and social isolation.
Women who come to the UK to join husbands will face tests after two and a half years - with failure meaning "they can't guarantee they will be able to stay" even if they have children, Mr Cameron told the BBC Radio 4 Today programme.
"You have to be able to speak a basic level of English now to come into the country as a husband or a wife.
"We have made that change already and we are now going to toughen that up so halfway through the five-year spousal settlement programme, there will be another opportunity to make sure your English is improving.
"You can't guarantee you will be able to stay if you are not improving your language.
"It is tough. But in the end it is not enough just to say the Government is going to spend more money and it is our responsibility. People coming to our country, they have responsibilities too."
He said: "I am not blaming the people who can't speak English. Some of these people have come to our country from quite patriarchal societies where perhaps the menfolk haven't wanted them to learn English, haven't wanted them to integrate.
"Where there is segregation, it is holding people back, it is not in tune with British values and it needs to go. We need to be more assertive."