Question

1. Van Gogh devoted himself to painting pictures,
2. van Gogh devoted himself to painting pictures,
3. Do you know about van Gogh.
4. Do you know about Van Gogh.
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Do we have to capitalize 'van'?
Which expressions are correct?

Answer 1

Capitalizing the “V” is standard in English, yes.

All are okay as long as you put question marks at the end of 3 and 4.

Answer 2

1. Van Gogh devoted himself to painting pictures,
2. van Gogh devoted himself to painting pictures,
3. Do you know about van Gogh?
4. Do you know about Van Gogh?

Answer 3

In the Netherlands, do they use #2 and #3?

Answer 4

I really don’t know.

In the US, when I see two-part names, both parts are usually capitalized. The only times I see lower case are in some Spanish names. Here are a few examples:

Van Buren
Di Carlo
Le Carre

But ~~> de la Fuente