Using the verb 'use' correctly

[Sylphidae]

Good day!

Got some questions on the top of my head.

1.) A.) It is used to make concrete and brick.
B.) It is use to make concrete and brick.

2.) A.) He used to be my hero.
B.) He use to be my hero.

3.) A.) What it is used for
B.) What it is use for

Please tell me which (and why) of the sentences or phrases in nos. 1-3 are correct.

[Torsten]

@sylphidae

1.) A.) It is used to make concrete and brick.
B.) It is use to make concrete and brick.

A) Is correct. (passive voice, simple present)

2.) A.) He used to be my hero.
B.) He use to be my hero.

A) Is correct. (used to expresses a habit or situation in the past)

3.) A.) What it is used for
B.) What it is use for

A) Is correct. (passive voice, simple present)
If it’s a question, it should read What is it used for?
Please tell me which (and why) of the sentences or phrases in nos. 1-3 are correct.

[YSaerTTEW443543]

TOEIC short conversations: Clarifying information on an invoice[YSaerTTEW443543]