Discurso indireto - reported speech: Como utilizar?

Wazzup guys? I read some topics in the forum but I still have some problems with "no backshift" (specially when using PERSON + SIMPLE PRESENT - HE SAYS THAT...), Its not clear to me in which moment should I use this.
I was studying this grammar in a book and found this:

- Theres no backshift of tenses when u r reporting something IN THE PRESENT. Examples:
(1) "I am trying to wash all the clothes" - He says (that) he IS TRYING to wash all the clothes
(2) "I like cooking" - He says (that) he LIKES cooking
(3) "We are lucky parents" - They said (that) they ARE lucky parents
(4) "I'll clean the house later" - He said (that) he WILL clean the house later

Numbers 3/4 are clear to me, because (in spoken english) in normal not to change tenses if the statement is still true, ryt?
Numbers 1/2 use this "HE SAYS THAT..." I just cant understand in which moment I use this part in the present or, normally, in the past.

I hope you understand my doubt, cause its even confusing to expose it, at least to me. :S

Thx in adv.