There are many ways of replying in the affirmative, I am afraid! But specific to your question:
ydy - “yes, it is / he is / she is” ydw - “yes, I am”
Er engraifft:
Ydy’r gath o dan y bwrdd? (Yes) - Is the cat under the table? (Ydy) Wyt ti o dan y bwrdd hefyd? (Yes) - Are you under the table too? (Ydw) Oes na gi o dan y bwrdd efo chdi? (Yes) - Is there a dog under the table with you? (Oes)
Ydw is used for 1st and 2nd person ydy is for third.
Ydw, dwi’n hoffi coffi. (Yes, I like coffee)
Ydw, ti’n gallu gneud rwybeth. (Yes, you can do something)
Ydy, ma hi’n dysgu Cymraeg. (yes, she’s learning Welsh).
Nadw and nagw are both for 1st and 2nd person just different ways to negate the sentence.
Nadw (Nagw), dwi ddim yn gallu i wneud e. (No, I can’t do it)
Nadw (nagw), ti ddim yn moyn mynd. (No, you don’t want to go)
For the third person it’s heard the same but written differently.
Nag yw, dyw e ddim yn siarad Cymraeg. (No, he doesn’t speak Welsh).
Well, I hope I understood you correctly and it helps.
Edit
Ups, I see @essenbee was faster then me and surely gave more accurate answer then I did so take his for granted @gavinM.
Edit deit
Now I’m not sure for 2nd person. Can someone correct me please? I’ve opened everything I have to disposal right now but couldn’t find if I’m correct or not.
My understanding is this, if I’m wrong, someone please correct me! (I’m on Course One Southern, Lesson 21 so not an expert!) For the present tense:
Ydw goes with the first-person form, I: Ydw, dw i’n… Yes, I am…
Ydy goes with the third-person form, he or she: Ydy, mae fe’n… Yes, he is… or Ydy, mae hi’n… Yes, she is…
Nadw and nagw are interchangeable, first-person: Nagw, dw i ddim yn… or Nadw, dw i ddim yn… No, I am not… Both correct, just different pronunciations. Iestyn seems to switch between them at random
You are spot on! You can use “ydw” for the 2nd person as well as yourself.
Just to add to the confusion (mua ha ha ha haaah!), we use “ydyn” for “ni” and “nhw”! Seriously though, if you’re not that far into the course yet @gavinM then DONT WORRY! When you reach this far it’ll be plain sailing for you!
Thank you, but don’t be. Go and read here Tatjana - Progress reports and you’ll see there’s nothing to be impressed about. What I’ve answered here in this topic is something what one should know if you wake him/her in the middle of the night especially after so much material I already went through.
“Ydw” is yes to questions such as “Wyt ti eisiau cwrw?”, “Ydach chi’n mynd?”. etc. So the questions tend to be in the 2nd person, the answers are in the 1st person, typically, unless you are talking to yourself
From the simple question to the Lord of Rings! Am I “Master” then? - hehe
And precious … I found those two words: “drud” and “gwerthfawr” from one little “University” dictionary. Which one suits better? Or is it none of them which does.
Not only a Slovenian habit, Tatjana, but a South African one as well! “Ja” is “yes” in the Afrikaans language, and I keep finding myself answering in the affirmative with “ja”. (Even though Afrikaans is not my first language, and I haven’t lived in SA for more than 30 years). Old habits die hard!