The word 'sy'

Can someone please give me an explanation as to when you would use the word ‘sy’. Some example sentences would help.

Sy’ (sydd is the full word) is one of the many aspects of bod (to be) and generally can be translated as that is.

So, Pwy sy’n galw? (something you might say when answering the 'phone) = Who (is it) that is calling?

And the answer to that might be Rob sy’ ma! = (It’s) Rob that is here!

Another example could be Y dyn sy’n rhedeg y ras = The man that is running the race (note that who is and that is are the same in Welsh).

As always, you’ll pick this subtle stuff up as you go along, entering into everyday conversations and listening to the radio, more than if you try and consciously learn it


The challenges introduce “sy” with sentences like “Dw i’n nabod rhwyun sy’n nabod dy chwaer di” and although we’d say this in English as “I know someone who knows your sister”, I find it more helpful to think of it as “I know someone who is knowing your sister” as it fits the idea that “sydd” means “who is” or “that is” better.


I like that explanation. Thank you StpehenBranley! My brain wants to shortcut the translation and say “who knows” or “that knows.”