Question

Подчеркните и укажите, к какому классу принадлежат местоимения. 1)If life takes an unexpected turn, a person discovers often that he can only depend on himself. 2)This is all I can say on the subject. 3)We can offer someone to do something, but we shouldn't force anyone. 4)Neither side has a motive to compromise at the moment. 5)One should always be careful when he operates this machine-tool.

Answer 1

1) he - personal pronoun (личное); himself - Reflexive pronoun (возвратное);  2) This - demonstrative pronoun (указательное); I - personal pronoun (личное); 
3) We - personal pronoun (личное); someone, something, anyone - Indefinite Pronouns (неопределенные); 
4) Neither - indefinite pronoun (неопределенное);  5) One - indefinite pronoun (неопределенное); he - personal pronoun (личное); this - demonstrative pronoun (указательное)

Answer 2

1. If life takes an unexpected turn, a person discovers often that he can only depend on himself. Class: Personal pronoun (third-person singular, masculine)

2. This is all I can say on the subject. Class: Demonstrative pronoun

3. We can offer someone to do something, but we shouldn't force anyone. Class: Personal pronoun (first-person plural)

4. Neither side has a motive to compromise at the moment. Class: Indefinite pronoun

5. One should always be careful when he operates this machine-tool. Class: Indefinite pronoun; Personal pronoun (third-person singular, masculine)

Note: In sentence 5, there is an inconsistency in the use of pronouns. It should be "One should always be careful when one operates this machine-tool" to maintain consistency with the use of the indefinite pronoun "One."