Welsh is a Celtic language that shares very few similarities with English making inter-comprehensibility limited to the use of some loan words or codeswitching into English by Welsh speakers.
The Annual Population Survey conducted by the Office for National Statistics for the year ending in March 2019 suggests that 874,600 Welsh residents (29 percent of the total population) aged three or over were able to speak Welsh. The results for the most recent National Survey for Wales (2017-2018) suggest that 19 per cent of the adult population aged 16 and over were able to speak Welsh, with an additional 12 per cent in this age group noting that they had "some Welsh speaking ability”. Both surveys give higher proportions of Welsh speakers in Wales than the decennial Census data in which 19% of the population aged three and above spoke Welsh in 2011.

The communities that continue to have higher percentages of Welsh speakers are found in the north and west of the country. However, in terms of number of speakers, most Welsh speakers live in densely populated urban areas in the south and east of the country. It is important to remember, therefore, that Welsh is a daily living language for people in every region and area of Wales. In addition, there are Welsh speakers around the world who use social media, mass media and online services. There are an estimated over 100,000 Welsh speakers in England alone. There is also an established community of around 50,000 people with Welsh heritage in Patagonia, Argentina with up to around 5,00 estimated to be Welsh speakers.

Since devolution in 1998 and establishment of the Welsh National Assembly, there has been cross-party consensus on the desirability of promoting the Welsh language in Welsh public life and ensuring its future prosperity. Today, the Welsh language has strong support in legislation. The 2011 Measure built on the foundations of the Welsh Language Act 1993 and now accords the Welsh language official status in Wales. Since 2011, the office of the Welsh Language Commissioner has been established and Welsh Language Schemes (previously administered by the Welsh Language Board) have been replaced by the Welsh Language Standards. Since 2015, there has been a Well-being of Future Generations (Wales) Act 2015 which sets a collective framework for public policy in Wales. That act promotes a vision of a Wales where the Welsh language thrives. Increasingly, Welsh legislation is paying attention to Wales’ statutory bilingual context. Following the establishment of the first state Welsh-medium primary school in 1947, the Welsh-medium education sector has grown rapidly across Wales, led primarily by parental demand and some education policymakers. There are over 500 Cylchoedd Meithrin providing Welsh-medium pre-school education and childcare to over 13,000 children throughout Wales. According to Government statistics, 16% of primary and secondary pupils in Wales attend Welsh-medium schools with a further 10% attending bilingual, dual medium or English with significant Welsh provision schools. The Welsh Government has a target to increase the percentage of each year group receiving Welsh medium education to 30% by 2031 and 41% by 2050 as part of its current aim to create a million Welsh speakers by 2050.