1. what: e.g. (1) asking for a subject complement; (2) asking for a sentence object
2. what: e.g. (1) as the object of a sentence; (2) ditto
3. that: e.g. (1) modifying an indefinite pronoun like iets, niets, alles or het enige; (2) modifying an adjective that is used as a noun, usually a superlative
4. which: e.g. (1) modifying the demonstrative pronouns dat and datgene; (2) referring back to an entire sentence
5. something: e.g. (1) as subject; (2) as subject complement

third-person singular present indicative of zijn; is, equals

the (definite article, masculine and feminine singular, plural)

1. of (possession, property)
2. of (general association)
3. by, of (creator)
4. from (origin)
5. from (starting point of a movement or change)
6. from (starting point in time)
7. from, off (removal of something from off something else)
8. of, out of, from, with (cause)
9. of, out of, with (material or resource)
10. of, out of, among (out of a larger whole; partitive)
11. from, was, formerly (indicating a change in price)
12. (colloquial) like (quotative (used to introduce direct speech))

1. that (masculine, feminine); referring to a thing or a person further away.
2. those (plural); referring to things or people further away.
3. (colloquial) a certain, a particular; some; this; referring to a thing or a person invisible or unknown to the audience.

1. A wagon, carriage.
2. A cart.
3. An automobile, car, van.
4. A sled, moving platform on wheels or rails a heavy machine etc. is mounted on
5. A load filling one of the above vehicles.