This section is not in the book. It is designed for my curious students, who want to know more.
It is useful to know parts of speech while learning Russian, because different parts of speech decline in a different way.
     There are 8 main parts of speech:  an adverb, an adjective, a conjunction, an interjection, a noun, a preposition, a pronoun, and a verb. 

 

      In Russian a noun, a pronoun, an adjective, and a verb decline.

      An adverb, a conjunction, an interjection, and a preposition stay the same. That is why it is important to distinguish them.

      Let’s have a look at them.

 

There are 10 of them (including Interrogative) in Russian:

 

я (I), ты (you-informal), он (he), она (she), оно (it), мы (we), вы (you-polite), они (they), кто who), что (what)

Russian Personal Pronouns decline depending on the gender, number and case.

 

Это мой телефон. = This is my phone.

Это твой телефон,  а это мой. = This is your phone and this is mine.

 

As you see, in Russian the same pronoun 'мой' is used for English 'my' and 'mine' .

 

(In English 'mine' is actually a possessive pronoun,  and 'my' is  a possessive adjective.)