Today, I will start a first level 4 lesson on the usage of “~shi”. This is use for a combination of 2 subjects like the following example :

Subject : I play tennis. I play golf. – Tenisu o shimasu. Gorufu o shimasu.
Q : Do you play sports? – Anata wa supo-tsu o shimasu ka?
A : Yes, I play tennis as well as golf – Hai, tenisu mo suru shi, gorufu mo shimasu
Meaning : Supo-tsu (Sports), Tenisu (Tennis), Gorufu (Golf)

The “~shi” is use to express “also”. In the above example, it means “I play tennis and also golf”. The “shi” can only be placed at the first verb and the second should be changed to “~masu” form. Another example with different style of sentence :

Q : Anything you would like to do? – Nani ga shitai koto ga arimasu ka?
A : Yes, but I don’t have money and also no time, so nothing can be done – Hai, demo okane mo nai shi, hima mo nai kara nani mo (dekiru)dekimasen.
Meaning : Koto (Things / Matters), Demo (But), Okane (Money), Hima (Free Time), Dekiru (Can Do)
~tai = This is use to express that you wish / want to do something. In this case Shitai = Suru + Tai (Suru should be changed to the Second Sound). Example : Asobu (Play)+ Tai = Asobitai (Wish to play). See the “bu (3rd sound)” is being changed to “bi (2nd sound)” (ba bi bu be bo)