Both the word ただ and だけ can often be translated as "just" or "only" in English. So what's the difference?

Patreon https://www.patreon.com/twowisemonkeysjapanesepodcast

Two Wise Monkeys Japanese Podcast

Ep.3 ただ vs だけ

This is a short conversation between  a student and a teacher.
 The script is as follows:
M: Hello, teacher, how are you? sà-wàt-dee kráp kroo bpen yang ngai bâang kráp
T: Hello, fine and you Meng? sà-wàt-dee kâ · sà-baai dee · láew Meng lá kâ
M: Life is fine. I have been to Thailand for 2 days. (ago)
      chee-wít sà-baai · sà-baai kráp · maa bprà-têt tai sŏng wan láew 
T: Are you coming for a visit, right?  maa tîieow châi măi?
 M: Not at all. I moved to work  here. mâi châi loiie kráp  pŏm yáai maa tam ngaan têe nêe
T: Very good. Tomorrow Thailand will have an important festival.
     Dee mâak · prûng-née bprà-têt tai jà mee têt-sà-gaan săm-kan
M: What is the festival? I've never been to Thailand in this period.
      têt-sà-gaan à-rai kráp · pŏm mâi koiie maa bprà-têt tai  chûuang née
T:   Songkran, do you know ?  sŏng-graan · róo jàk măi
M:  I've never heard,  what is it?  mâi koiie dâai yin · keu à-rai kráp
T: Thai New Year's Day Tourists know that Songkran is a water play day for Thai people.
       wan bpee mài tai · nák tông tîieow róo jàk sŏng-graan keu wan lên náam kŏng kon tai
M: Very interesting, I'm glad to be able to visit Songkran Festival.
      nâa sŏn jai mâak · pŏm dee jai têe jà dâai tîieow têt-sà-gaan sŏng-graan
T: not just play with water. We have many activities such as going to the temple to make merit. release the bird, release the fish,  visit family , pay respect to parents and elders and carry sand into the temple
   mâi châi kâe lên náam · rao mee gìt-jà-gam lăai yàang · chên · bpai tam bun têe wát · bplòi nók bplòi bplaa · bpai yîiam krôp kruua · wâai pôr mâe láe pôo sŏong aa-yú láe kŏn saai kâo wát
M: Really excited! Tomorrow I will go to the city and temple to see the Songkran atmosphere.
     róo sèuk dtèun dtên jing jing · prûng-née pŏm jà bpai nai meuuang láe wát · pêuua doo ban-
     yaa-gàat
     Sorry, I have to go. I have an appointment with my boss.
     kŏr tôht kráp · pŏm dtông bpai láew · pŏm mee nát gàp jâo naai kráp

Learning Thai with Kru Tarntawan

Conversation about Songkran Festival

Do you want to know how to say Good Bye in Thai? Let's listen to this Episode. I hope you can greet in Thai after you listen to my episodes. Enjoy!