1. Japanese i-adjective conjugations
Informal
Japanese i-adjective conjugations

2. First things first !
Know that there are two types of adjectives, and two types of speech in Japanese (formal speech/informal speech)
1. i-adjectives
2. na-adjectives
I will cover (informal) i-adjectives in this lesson

3. The rules for conjugating i-adjectives (Present affirmative (informal)
This one is easy because you do absolutely nothing to change the adjective!
Ex: ureshii stays ureshii
Ex sentence: watashi wa ureshii.
(I am happy.) 

4. Rules for conjugating i-adjectives (Present Negative(informal)
1. Drop the final ( i ) from the adj.
2. Add ku nai
Ex: ureshii  drop the final i
ureshiku nai  add ku nai
Ex sentence: watashi wa ureshiku nai.
( I am not happy. ) 

5. Rules for conjugating i-adjectives (Past affirmative (informal)
1. Drop the final ( i ) from the adj.
2. Add katta
Ex: ureshii drop the final i
ureshikatta  add katta
Ex sentence:  watashi wa ureshikatta.
( I was happy. )

6. Rules for conjugating i-adjectives (Past Negative (informal)
1. Drop the final ( i )
2. Add ku nakatta
Ex: ureshii  ureshiku nakatta
Ex sentence: watashi wa ureshiku nakatta.
( I was not happy.) 

7. BRACE YOURSELF!
Here come examples of common i-adjectives for you to practice with. They are written in all the 4 tenses we’ve covered. 1. Present Affirmative /2. Present Negative 3.Past Affirmative / 4. Past Negative

8. Takai= expensive Takai= is expensive Takakunai=not expensive
Takakatta=was expensive
Takaku nakatta= was not expensive

9. Yasui=cheap Yasui= is cheap Yasuku nai= is not cheap
Yasukatta= was cheap
Yasuku nakatta= was not cheap

10. Ureshii=happy Ureshii= is happy Ureshiku nai= is not happy
Ureshikatta = was happy
Ureshiku nakatta= was not happy

11. Oishii = delicious (good tasting)
Oishii = is delicious
Oishiku nai = is not delicious
Oishikatta = was delicious
Oishiku nakatta = was not delicious

12. Mazui= bad tasting Mazui = is bad tasting
Mazuku nai = is not bad tasting
Mazukatta = was bad tasting
Mazuku nakatta = was not bad tasting

13. Kanashii= sad Kanashii = is sad Kanashiku nai= is not sad
Kanashikatta= was sad
Kanashiku nakatta= was not sad

14. Atsui= hot Atsui = is hot Atsuku nai = is not hot Atsukatta= was hot
Atsuku nakatta= was not hot

15. Samui= cold Samui= is cold Samuku nai= is not cold
Samukatta = was cold
Samuku nakatta= was not cold

16. Chiisai= small Chiisai= is small Chiisaku nai = is not small
Chiisakatta= was small
Chiisaku nakatta= was not small

17. Ookii = big Ookii = is big Ookiku nai = is not big Ookikatta= was big
Ookiku nakatta = was not big

18. Akarui = bright Akarui= is bright Akaruku nai = is not bright
Akarukatta = was bright
Akaruku nakatta= was not bright

19. Kurai = dark Kurai = is dark Kuraku nai = is not dark
Kurakatta= was dark
Kuraku nakatta = was not bright

20. Isogashii= busy Isogashii = is busy Isogashiku nai = is not busy
Isogashikatta = was busy
Isogashiku nakatta = was not busy

21. Tanoshii = fun/pleasant
Tanoshii = is fun
Tanoshiku nai = is not fun
Tanoshikatta = was fun
Tanoshiku nakatta = was not fun

22. Hayai = fast Hayai = is fast Hayaku nai = is not fast
Hayakatta = was fast
Hayaku nakatta = was not fast

23. Osoi = slow Osoi = is slow Osoku nai = is not slow Osokatta = was slow
Osoku nakatta= was not slow

24. ii= good ii= is good Yoku nai= is not good Yokatta = was good
Yoku nakatta = was not good

25. Warui= bad Warui = is bad Waruku nai = is not bad Warukatta = was bad
Waruku nakatta = was not bad

26. Atarashii= new Atarashii = is new Atarashiku nai = is not new
Atarashikatta= was new
Atarashiku nakatta = was not new

27. Furui= old Furui = is old Furuku nai = is not old Furukatta = was old
Furuku nakatta= was not old

28. Yasashii = easy Yasashii= is easy Yasashiku nai = is not easy
Yasashikatta = was easy
Yasashiku nakatta = was not easy

29. Muzukashii= difficult
Muzukashii= is difficult
Muzukashiku nai = is not difficult
Muzukashikatta= was difficult
Muzukashiku nakatta = was not difficult

30. Omoshiroi = interesting
Omoshiroi = is interesting
Omoshiroku nai= is not interesting
Omoshirokatta= was interesting
Omoshiroku nakatta = was not interesting

31. tsumaranai= boring Tsumaranai = is boring
Tsumaranaku nai= is not boring
Tsumaranakatta= was boring
Tsumaranaku nakatta= was not boring

32. Tooi= far/distant Tooi= is far Tooku nai= is not far
Tookatta = was far
Tooku nakatta = was not far

33. Chikai= close Chikai= is close Chikaku nai = is not close
Chikakatta = was close
Chikaku nakatta= was not close

34. Itai= painful Itai= is painful Itaku nai= is not painful
Itakatta = was painful
Itaku nakatta = was not painful

35. Amai=sweet Amai= is sweet Amaku nai = is not sweet Amakatta= was sweet
Amaku nakatta= was not sweet

36. Suppai= sour Suppai= is sour Suppaku nai= is not sour
Suppakatta = was sour
Suppaku nakatta = was not sour

37. Omoi = heavy Omoi = is heavy Omoku nai = is not heavy
Omokatta = was heavy
Omoku nakatta = was not heavy

38. Karui = light (for weight)
Karui= is light
Karuku nai = is not light
Karukatta = was light
Karuku nakatta = was not light

39. Semai = narrow Semai = is narrow Semaku nai = is not narrow
Semakatta = was narrow
Semaku nakatta = was not narrow

40. hiroi = wide Hiroi = is wide Hiroku nai = is not wide
Hirokatta = was wide
Hiroku nakatta = was not wide

41. Translate the following words in ( informal )japanese with their
proper conjugations. Ex: Is happy = ureshii
Is far =
Is cold =
Is big =
Is hot =
Is fun =
Is busy =
Is bright =
Is cheap =
Is delicious =
is good =

42. Translate the following words in ( informal )japanese with their
proper conjugations. Ex: Is not happy = ureshiku nai
Is not cold =
Is not far =
Is not busy =
Is not big =
Is not hot =
Is not expensive=
Is not good = *note, negative tense of yoi(good) must be used here, ii(good) can only be used in the present affirmative tense.
Is not small =
Is not new =
Is not delicious =

43. Ex: Was far = tookatta Was happy = Was big = Was delicious =
Was good =
Was bad=
Was busy =
Was wide =
Was fun =
Was cheap=
Was sweet =

44. Ex: Was not expensive = takaku nakatta
Was not far =
Was not small =
Was not heavy =
Was not dark =
Was not happy =
Was not near =
Was not busy =
Was not delicious =
Was not fun =
Was not cheap =