Past Future Tense

We add past tense after future tense.
İf the last vowel is ‘’e,i,ö,ü’’(thin vowels) then it must be ‘’ecekti’’, if last vowel is ‘’ a,ı,o,u ’’(thick vowels) then it must be ‘’acaktı’’

(Ben) Gidecektim =İ would go (Biz) Gidecektik=We would go
(Sen) Gidecektin= You would go (Siz) Gidecektiniz=You would go
(O) Gidecekti =She would go (Onlar) Gidecektiler =They would go

Yapacaktı= he would do

Negative Sentence
İf the last vowel is ‘’e,i,ö,ü’’(thin vowels) then it must be ‘’meyecekti’’, if last vowel is ‘’ a,ı,o,u ’’(thick vowels) then it must be ‘’mayacaktı’’
y is linking consonant here
(Ben) Gitmeyecektim =İ would not go (Biz) Gitmeyecektik=We would not go
(Sen) Gitmeyecektin= You would not go (Siz) Gitmeyecektiniz=You would not go
(O) Gitmeyecekti =She would not go (Onlar) Gitmeyecektiler =They would not go

Yapmayacaktı =he would not do

Pozitive Questions
( Where,Why, What, Which,When Who, How,How much, How many,whom ) are added to pozitive sentence to make pozitive questions.

Nasıl yüzecektin = how would you swim

mi or mı is added to pozitive sentence. for they mı is added to sentence.
İf the last vowel is ‘’e,i,ö,ü’’(thin vowels) then it must be ‘’miydi’’, if last vowel is ‘’ a,ı,o,u ’’(thick vowels) then it must be ‘’ mıydı’’

(Ben) Gidecek miydim? =would i go? (Biz) Gidecek miydik? =would we go?
(Sen) Gidecek miydin ?= would you go ? (Siz) Gidecek miydiniz? = would you go ?
(O) Gidecek miydi ? =would she go ? (Onlar)Gidecekler miydi? = would they go ?

yapacak mıydık ? would we do?

Negative Questions
( Where,Why, What, Which,When Who, How,How much, How many,whom ) are added to negative sentence to make negative questions.

Nasıl gelmeyeceklerdi = how would not they come

İf the last vowel is ‘’e,i,ö,ü’’(thin vowels) then it must be ‘’miydi’’, if last vowel is ‘’ a,ı,o,u ’’(thick vowels) then it must be ‘’mıydı’’

(Ben) Gitmeyecek miydim? =would i not go? (Biz) Gitmeyecek miydik? =would not we go?
(Sen) Gitmeyecek miydin ?= would not you go ? (Siz) Gitmeyecek misiniz? = would not you go ?
(O) Gitmeyecek miydi ? =would not she go ? (Onlar)Gitmeyecekler miydi? = would not they go ?

yapmayacak mıydık ? would not we do ?

Great explained.

I would never do that-Bunu hiç yapmadım?
If is that so,why it doesn´t: Bunu hiç yapardım OR yapacaktım.?

Bunu hiç yapmazdım/yapmayacaktım.

hiç is not enough to negate a sentence, there always has to be a negative marking in the verb also.

My thoughts are the translation of Bunu hiç yapmadım is

I never did this / I have never done this

and I agree with Abla´s translation of 

I would never do this as

Bunu hiç yapmazdım/yapmayacaktım

Thank´s Abla and Henry.
The double negation,that´s also we have in Serbian,it´s not like in English,but when I translate from English into Turkish,I forget about it... 

One time,I asked Abla how to say ´´ I would never do that´´.
She told me that it should be Bunu hiç yapmazdım. But I´ve read it without Z.

Unfortunately my ´English trained´ brain also has problems with double negation. I would never not do that = I would always do that 

I have a theory. I think "hiç" is not negative. It is positive. And it means "ever" Because:

1)It doesn´t make the sentence negative alone.

2)And it doesn´t make sense when you use it with a positive predicate.

I wait for the objections

Well it has some fifty negative meanings as an independent word, from none to never.

hiç can be used with positive predicates  -  in questions:

                                Hiç parasütle atladın mı?

I have thought of hiç as an emphasizing word which strongly gravitates to negative environments. So strongly that it hardly has any use in affirmative sentences. (The pronoun kimse also likes to go where the light is red.)

In the sentence above I think hiç is there to make the sentence more polite: it gives the listener a chance to answer no without losing his face. But this is just a guess and Turks know better.

Then let me improve my theory: It has a positive meaning when it is an adverb. Objections?