Inactive Tutor answered 08/17/26
In Word for Mac, select the text (or ⌘A for the whole document), then go to:
Tools → Language → English (UK) → OK
If available, choose Default to make English (UK) the default for future documents.
The key point: changing the dictionary itself isn’t the normal way to switch spell-check languages—you set the proofing language for the text/document.