В детстве я мечтал стать художником и много рисовал карандашами.

In childhood I dreamed of becoming an artist and drew a lot with pencils.

Breakdown of В детстве я мечтал стать художником и много рисовал карандашами.

• я: I
• в: in
• и: and
• много: much

Questions & Answers about В детстве я мечтал стать художником и много рисовал карандашами.

What does в детстве literally mean, and why is детстве in that form?

В детстве literally means in (my) childhood.

• детстве is the prepositional case of детство (childhood).
• The preposition в
  • prepositional is commonly used to talk about time periods when something happened:
    
    • в детстве – in childhood
    • в молодости – in youth
    • в прошлом году – last year

If you said в детство (accusative), it would mean into childhood (direction, movement), which doesn’t fit here. For a time reference, you need в детстве.

What tense and form is мечтал, and how would it change for a woman or for plural?

Мечтал is:

• past tense
• imperfective aspect (from the verb мечтать)
• masculine singular form

So я мечтал implies that the speaker is male.

Other forms:

• Feminine singular: я мечтала
• Neuter singular (for neuter subjects, not people): оно мечтало
• Plural (any mixed or all-male group): мы мечтали, они мечтали

So a woman would naturally say:

• В детстве я мечтала стать художником…