Nearly 140,000 people living in England and Wales, around half a percent of the population, cannot speak English at all the 2011 Census has shown.
English is not the main language for about four million residents (8% of the population), the data showed.
After English, the second most prevalent language was Polish, spoken by 1% of the population - a total of 546,000 people.
This was followed by Punjabi and Urdu.
The 2011 Census was the first to ask how well people could speak English when this was not their main form of communication.
Figures released by the Office for National Statistics (ONS) showed 138,000 residents could not speak the language at all.
Some 726,000 had a weak grasp of English.
Around 1.6 million could speak the language "well" while around 1.7 million could speak it "very well".
It was the main language for 92% of residents (50 million people) aged three or older.
The Census found 49 different tongues were used as the main form of communication by groups of more than 15,000 people.
The main 20 languages spoken by people in the UK
- English (English or Welsh if in Wales) 49,808,000 or 92.3% of the population
- Polish 546,000 or 1%
- Punjabi 273,000 or 0.5%
- Urdu 269,000 or 0.5%
- Bengali (with Sylheti and Chatgaya) 221,000 or 0.4%
- Gujarati 213,000 or 0.4%
- Arabic 159,000 or 0.3%
- French 147,000 or 0.3%
- All other Chinese (excludes Mandarin and Cantonese) 141,000 or 0.3%
- Portuguese 133,000 or 0.2%
- Spanish 120,000 or 0.2%
- Tamil 101,000 or 0.2%
- Turkish 99,000 or 0.2%
- Italian 92,000 or 0.2%
- Somali 86,000 or 0.2%
- Lithuanian 85,000 or 0.2%
- German 77,000 or 0.1%
- Persian/Farsi 76,000 or 0.1%
- Tagalog/Filipino 70,000 or 0.1%
- Romanian 68,000 or 0.1%
Of the top five languages, three were South Asian.
Meanwhile, a small number of people (22,000) used sign language.
A regional breakdown found 22% (1.7 million) of Londoners used a main language other than English.
English was not the main language in 4% of homes in England and Wales - one million households.
Around 47% of the adult population (21 million people) were married in 2011 - this was down on the 51% who were married 10 years earlier, when the number also stood at 21 million.
In 2011, there were some 23.4 million households in England and Wales - an increase of 8% from almost 22 million in 2001.
Notable changes over the ten-year period include a rise in the number of homes comprising unrelated adults or more than one family.
This figure jumped 28% between 2001 and 2011, according to the data.
Meanwhile, there was a fall in the number of one-person households among those aged 65 or older and among those aged 16-34.
In the older age group, this figure dropped 2.8 percentage points and among those in their late teens to early thirties, it declined by 2.5 percentage points.
However, there was an increase - by six percentage points - in the number of 35-to-64-year-olds living alone.
The latest statistics also revealed details relating to the population's commuting habits.
In 2011, the majority of 16-to 74-year-olds in England and Wales drove a car or van to work (58% or 15 million people).
The second most reported method of travel was by foot (11% or 2.8 million people).
Travel by bus, minibus or coach was the next most popular option.
In London, 50% of the population (two million people) used public transport to get to work, compared with 31% (1.3 million people) who travelled by car, motorcycle or taxi.
Outside London, the percentage of workers who favoured public transport ranged from 6% (162,000 people) in the South West to 13% (151,000 people) in the North East.
Those using cars, motorcycles or taxis ranged from 67% (2.8 million) in the South East to 75% (1.0 million) in Wales.Suggest a correction