These particles are used to distinguish the different roles that words have in the sentence.’Wa’ indicates the main topic of the sentence, what we are talking about.
Watashi wa americajin desu – I am American
Karera wa tomodachi desu – They are friends
‘Ga’ specifically indicates the subject..
Neko ga imasu – There is a cat
Hon ga arimasu – There is a book
‘No’ indicates possession or the genitive
Ryōri no hon – Cook book
Watashi no tsukue – My desk
*Note that in Japanese there are no articles’O’ indicates the direct object
Hon o yomimasu – I read a book
Eiga o mimasu – I watch a film
‘Mo’ is a conjunction (too, as well, also)
Tamago mo tabemasu – I also eat eggs
Inu mo imasu – There is a dog too