This technique is perhaps most useful for advanced students, but for the adventurous intermediate student it can give a broad sense of the possibilities, and access to vocabulary which you can explore further with the help of the Gweiadur and Geiriadur Prifysgol.
The goal is finding usage examples for new words you have learned but want to know more about in the context of actual Welsh usage. Searching in the online archives of Welsh language publications can turn up all sorts of real-life Welsh.
The Gweiadur offers a sidebar titled, “Dictionary Portal” which you can see to the right on this page. The external databases offered by the Portal, however, are on the scholarly, professional and/or political side. Finding more colloquial usage examples is not hard, however, if you make your search focus on any of several online archives of Welsh language periodicals.
Here are some examples, that you can cut and paste right into your browser search field, at the top of your browser page. These examples use the word “sef” and the pair “erbyn hyn”, but you can put any word or phrase you want inside the double quotes.
golwg360 “sef”
parallel.cymru “sef”
dyffryn nantlle “sef”
cymdeithaseryri “sef”
barn.cymru “sef”
cymdeithaseryri “erbyn hyn”
dyffryn nantlle “erbyn hyn”
As you explore these examples, you’ll find that more sites are turned up than just the publications themselves. I’ve found that these further sites generally also have good standards for well-formed Welsh, so it’s a productive way to explore Welsh in its native, well-written expression.