Good morning fellow learners
I have got a friend who wanted to tell you what to do yesterday =
mae gyda fi ffrind oedd yn moyn dweud wrthot ti beth i wneud ddoe
I didnt originally put in the “i” after the word “beth” but when I double checked myself, a certain translation tool inserted it. Is it needed and why?
Please and thank you 
in advance.
Chris.
The short answer is “yes”.
I’m not really sure what the longer answer is, though. I’ve always put it down to “that’s how Welsh does things”, but perhaps other people have more helpful explanations?
It confuses my tiny little English brain because I think of “Gwneud” as already being “to do”, so I automatically disclude the addition “to” (i).
I guess I will just have to learn to think more Welsh-like
Thank you for your response Sara.
It’s something that gets asked a lot on here. Here’s just one of the threads that might help https://en.forum.saysomethingin.com/t/when-to-use-and-when-not-to-use-i-as-a-preposition-before-a-verbnoun
If it helps at all, what we think of in English as being a “verb” is more properly called in Welsh a “verbnoun”.
Which I think means that it fulfills the function of “think” in “tell me what to think” but also the function of what we would call a “gerund”, so the “thinking” in “thinking is the most important thing”.
This. I think the underlying structure of beth i wneud is actually ( pa ) beth i('w) wneud - literally, “what thing, for its doing” or “what thing, for the doing of it”.
(Translating word for word will make you sound like Yoda.)