Learning Welsh at the C1 level is an exciting journey that delves deep into the intricacies of the language, its unique idioms, and cultural nuances. At this stage, your understanding of Welsh should be robust, allowing you to communicate effectively in various contexts. To help you reach this advanced level, we’ve compiled a list of 50 essential words that will enrich your vocabulary and enhance your fluency. Each word is carefully selected to ensure it covers a broad spectrum of daily and academic use.

1. Cyflawni

**Cyflawni** means “to accomplish” or “to achieve.” At the C1 level, you might use it in sentences like: “Rwy’n gobeithio cyflawni fy nodau eleni” (I hope to achieve my goals this year).

2. Cynnal

**Cynnal** translates to “to maintain” or “to hold.” It can be used in various contexts, such as: “Mae angen cynnal y tŷ’n lân” (The house needs to be kept clean).

3. Cyfrannu

**Cyfrannu** means “to contribute.” For example: “Mae pawb yn cyfrannu at y prosiect” (Everyone is contributing to the project).

4. Diffinio

**Diffinio** translates to “to define.” You might say: “Mae’n anodd diffinio cariad” (It’s hard to define love).

5. Dysgu

**Dysgu** means “to learn” or “to teach,” depending on the context. An example would be: “Rwy’n dysgu Cymraeg” (I am learning Welsh).

6. Ymchwilio

**Ymchwilio** translates to “to research.” For instance: “Mae angen i ni ymchwilio i’r pwnc hwn” (We need to research this topic).

7. Cyfathrebu

**Cyfathrebu** means “to communicate.” An example could be: “Mae cyfathrebu da yn hanfodol mewn perthynas” (Good communication is essential in a relationship).

8. Cyflwyno

**Cyflwyno** means “to present” or “to introduce.” For example: “Roeddwn i’n nerfus i gyflwyno fy hun” (I was nervous to introduce myself).

9. Datblygu

**Datblygu** translates to “to develop.” You might use it in a sentence like: “Rydym yn datblygu prosiect newydd” (We are developing a new project).

10. Darganfod

**Darganfod** means “to discover.” For instance: “Rwy’n darganfod pethau newydd bob dydd” (I discover new things every day).

11. Cymryd

**Cymryd** means “to take.” An example would be: “Mae’n rhaid i chi gymryd eich meddyginiaeth bob dydd” (You must take your medication every day).

12. Cael

**Cael** translates to “to get” or “to receive.” For instance: “Rwy’n falch eich bod chi’n cael eich cyflog” (I’m glad you’re getting your salary).

13. Cynnig

**Cynnig** means “to offer.” An example could be: “Fe wnaethon nhw gynnig help” (They offered help).

14. Cyflogaeth

**Cyflogaeth** translates to “employment.” For example: “Mae cyflogaeth yn bwysig i’r economi” (Employment is important for the economy).

15. Datrysiad

**Datrysiad** means “solution.” You might use it in a sentence like: “Rydym yn chwilio am ddatrysiad i’r broblem” (We are looking for a solution to the problem).

16. Penderfyniad

**Penderfyniad** translates to “decision.” For instance: “Mae gwneud penderfyniad yn gallu bod yn anodd” (Making a decision can be difficult).

17. Adnoddau

**Adnoddau** means “resources.” An example would be: “Mae llawer o adnoddau ar gael i fyfyrwyr” (There are many resources available to students).

18. Cyfrifoldeb

**Cyfrifoldeb** translates to “responsibility.” For instance: “Mae gan bob gweithiwr gyfrifoldebau penodol” (Every worker has specific responsibilities).

19. Cydweithio

**Cydweithio** means “to collaborate.” An example could be: “Mae’r tîm yn cydweithio’n dda” (The team collaborates well).

20. Gofyn

**Gofyn** translates to “to ask.” For instance: “Mae’n bwysig gofyn cwestiynau” (It’s important to ask questions).

21. Rheoli

**Rheoli** means “to manage.” An example would be: “Mae angen i chi rheoli eich amser yn dda” (You need to manage your time well).

22. Cynllunio

**Cynllunio** translates to “to plan.” For instance: “Rydym yn cynllunio taith i’r Eidal” (We are planning a trip to Italy).

23. Cynyddu

**Cynyddu** means “to increase.” An example could be: “Mae’r prisiau yn cynyddu’n gyson” (The prices are constantly increasing).

24. Lleihau

**Lleihau** translates to “to reduce.” For instance: “Mae angen lleihau gwastraff plastig” (We need to reduce plastic waste).

25. Cynnal

**Cynnal** means “to sustain” or “to support.” An example would be: “Mae’n bwysig cynnal iechyd da” (It’s important to maintain good health).

26. Addasu

**Addasu** translates to “to adapt.” For instance: “Mae pobl yn gorfod addasu i newidiadau” (People have to adapt to changes).

27. Cynnig

**Cynnig** means “to propose.” An example could be: “Fe wnaethon nhw gynnig syniad newydd” (They proposed a new idea).

28. Cyhoeddi

**Cyhoeddi** translates to “to publish.” For instance: “Mae’r llyfr newydd wedi’i gyhoeddi” (The new book has been published).

29. Datgan

**Datgan** means “to declare.” An example would be: “Fe wnaethon nhw ddatgan eu bwriadau” (They declared their intentions).

30. Dathlu

**Dathlu** translates to “to celebrate.” For instance: “Rydym yn dathlu ein pen-blwydd” (We are celebrating our anniversary).

31. Darganfod

**Darganfod** means “to discover.” An example could be: “Mae’n wych darganfod lleoedd newydd” (It’s great to discover new places).

32. Gweithredu

**Gweithredu** translates to “to implement” or “to take action.” For instance: “Mae angen gweithredu’r cynllun newydd” (The new plan needs to be implemented).

33. Cyflwyno

**Cyflwyno** means “to submit.” An example would be: “Mae angen cyflwyno’r adroddiad erbyn dydd Gwener” (The report needs to be submitted by Friday).

34. Cynnal

**Cynnal** translates to “to hold” or “to conduct.” For instance: “Rydym yn cynnal cyfarfod bob wythnos” (We hold a meeting every week).

35. Cyflawni

**Cyflawni** means “to achieve.” An example could be: “Mae’n bwysig cyflawni eich nodau” (It’s important to achieve your goals).

36. Cyfrannu

**Cyfrannu** translates to “to contribute.” For instance: “Mae pawb yn cyfrannu at y gwaith tîm” (Everyone is contributing to the team work).

37. Cynnal

**Cynnal** means “to sustain” or “to uphold.” An example would be: “Mae’n bwysig cynnal cydbwysedd rhwng gwaith a bywyd” (It’s important to maintain a work-life balance).

38. Datblygu

**Datblygu** translates to “to develop.” For instance: “Rydym yn datblygu strategaethau newydd” (We are developing new strategies).

39. Datrysiad

**Datrysiad** means “solution.” An example could be: “Rydym yn chwilio am ddatrysiad ar gyfer y broblem” (We are looking for a solution to the problem).

40. Penderfyniad

**Penderfyniad** translates to “decision.” For instance: “Mae gwneud penderfyniad yn hanfodol” (Making a decision is crucial).

41. Adnoddau

**Adnoddau** means “resources.” An example would be: “Mae llawer o adnoddau ar gael ar-lein” (There are many resources available online).

42. Cyfrifoldeb

**Cyfrifoldeb** translates to “responsibility.” For instance: “Mae gan bob un ohonom gyfrifoldebau i’r gymuned” (Each of us has responsibilities to the community).

43. Cydweithio

**Cydweithio** means “to collaborate.” An example could be: “Mae cydweithio’n hanfodol ar gyfer llwyddiant” (Collaboration is essential for success).

44. Gofyn

**Gofyn** translates to “to ask.” For instance: “Peidiwch ag ofni gofyn cwestiynau” (Don’t be afraid to ask questions).

45. Rheoli

**Rheoli** means “to manage.” An example would be: “Mae angen rheoli’r adnoddau’n effeithiol” (Resources need to be managed effectively).

46. Cynllunio

**Cynllunio** translates to “to plan.” For instance: “Mae cynllunio ymlaen llaw yn hanfodol” (Planning ahead is essential).

47. Cynyddu

**Cynyddu** means “to increase.” An example could be: “Mae’r galw am wasanaethau’n cynyddu” (The demand for services is increasing).

48. Lleihau

**Lleihau** translates to “to reduce.” For instance: “Mae angen lleihau’r defnydd o blastig” (We need to reduce the use of plastic).

49. Cynnal

**Cynnal** means “to sustain” or “to support.” An example would be: “Mae’n hanfodol cynnal iechyd da” (It’s essential to maintain good health).

50. Addasu

**Addasu** translates to “to adapt.” For instance: “Mae angen i ni addasu i’r amgylchiadau newydd” (We need to adapt to the new circumstances).

In conclusion, mastering these 50 essential words will significantly enhance your Welsh vocabulary and fluency at the C1 level. By incorporating these words into your daily conversations and written communication, you will find yourself better equipped to handle complex topics and engage in more meaningful discussions. Remember, language learning is a journey, and every new word you learn brings you one step closer to fluency. Happy learning!