What is a English language …

The language requirements for a Skilled Worker Visa depend on the job you are applying for and can be found on the visa requirements page of the UK Government. Generally, a Skilled Worker Visa applicant must demonstrate that they have satisfactory proficiency in English as a requirement for meeting the criteria for the role. This can either include passing a recognised English language test or showing prior evidence of being able to communicate in English, such as qualifications in English literature or language or similar.

Source: UK Government Guidance on Immigration Rules - Skilled Workers section