The UK must go further to ensure those settling learn English "so they can be more integrated into our country".
Asked about the issue at Prime Minister's Questions, Mr Cameron said the last government had made progress on the issue, but more had to be done.
He agreed parents should be responsible for making sure children speak English.
Conservative MP for Keighley Kris Hopkins asked if the PM agreed that there was "a responsibility and an obligation" on parents to make sure their children can speak English when they start school.
Mr Cameron replied: "I completely agree... in too many cases this isn't happening."
Since last autumn, people from outside the EU applying for a visa to join their spouse or partner now have to prove they have a basic command of English before their application is approved.
Previously, visa applicants had to show only that their marriage or partnership was genuine and that they could financially support themselves.
The prime minister told the Commons: "The last government did make some progress on making sure people learnt English when they came to our country, I think we need to go further.
"If you look at the figures for the number of people who are brought over as husbands and wives, particularly from the Indian sub-continent, we should be putting in place - and we will be putting in place -  tougher rules to make sure they do learn English and so when they come, if they come, they can be more integrated into our country."
The weekly session of Prime Minister's Questions was dominated by foreign affairs with Labour leader Ed Miliband focusing all his six questions on events in Egypt and the UK's mission in Afghanistan.
Mr Miliband, who visited Afghanistan for the first time as Labour leader last week, paid an extended tribute to soldiers' work there, acknowledged the difference in the Commons session from the normal political point scoring.
Mr Cameron welcomed the opportunity to have a "serious conversation" about the work of British soldiers in Afghanistan, saying they wanted politicians to discuss their efforts, although he also noted  many MPs often "preferred a bunfight" about domestic issues.

The 14-time major champion, playing in his first full PGA Tour event for almost 18 months, carded a level-par second round of 72, but missed the cut by four shots after his first-round 76.
World number one Jason Day and US Open champion Dustin Johnson also missed the cut at Torrey Pines in San Diego.
Overnight leader Rose carded a one-under 71 to put him on eight under.
Canada's Adam Hadwin and USA's Brandt Snedeker are tied in second on seven under, while US PGA champion Jimmy Walker missed the cut as he finished on three over.
Woods is playing in just his second tournament since 15 months out with a back injury.
"It's frustrating not being able to have a chance to win the tournament," said the 41-year-old, who won his last major, the US Open, at the same course in 2008.
"Overall today was a lot better than yesterday. I hit it better, I putted well again. I hit a lot of beautiful putts that didn't go in, but I hit it much better today, which was nice."
Scotland's Martin Laird and England's Paul Casey are both on two under, while Ireland's Shane Lowry is on level par.

Jonathan Forte hit the post for the visitors, who are six points above the bottom four, before Tareiq Holmes-Dennis sent an effort wide.
Oldham keeper Joel Coleman saved a David Worrall shot at the other end.
Main fired home after the hour mark as he latched on to Forte's pass to seal victory for the Latics.
Oldham have a sizeable cushion above the League One relegation places with three games left to play, while Southend remain in 13th place.

Storms smashed a hole in the sea wall alongside the line above the seafront in Dawlish, south Devon in 2014.
The railway line took two months to repair at an estimated cost of £1bn to the local economy.
Network Rail is consulting with Devon and Cornwall residents about the plans.
They include strengthening defences and cliffs, as well and building breakwaters to protect the line.
More on the coastal rail protection work, and other Devon and Cornwall news
Cliffs next to the line would be stabilised and reshaped so they are not as steep under the plans.
A total of £270m is allocated for spending on priority areas including around Dawlish between 2019 and 2024.
The line connects Devon and Cornwall with the rest of the UK.
David Cameron has said too many children from immigrant families are not able to speak English when they start at school.
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Protecting a key coastal railway track from rising sea levels and falling cliffs is going to cost about £650m, Network Rail has said.