1. I am looking for a big house which I can live in.

2. I am looking for a big house to live in.

3. I am looking for a big house which to live in.

4. I am looking for a big house in which to live.

(Sentence 1 is a complex sentence. The others are simple sentences. Are all the sentences grammatical and do they have the same meaning?)

1 is awkward ~~> I am looking for a big house in which to live.

2 is fine.

3 is incorrect; see #1.

4 is fine; see #1.

Complex sentences = 1 and 4.
Simple sentence = 2.
Incorrect = 3.

Try not to end sentences with prepositions, which are designed to relate to objects ("live in" what?).

I hope this helps a little more. Thanks for asking.

All of the sentences are grammatically correct, but they do have slightly different meanings.

Sentence 1: "I am looking for a big house which I can live in." This sentence is a complex sentence, as it consists of a main clause ("I am looking for a big house") and a relative clause ("which I can live in"). The relative clause provides additional information about the big house you are looking for. The usage of "which" suggests that you are looking for any big house that you can live in, without any specific preference or restriction.

Sentence 2: "I am looking for a big house to live in." This is a simple sentence. It conveys the same main message as the first sentence - you are searching for a big house to live in. However, the use of "to" suggests that your primary intention is to find a big house specifically for the purpose of living in it.

Sentence 3: "I am looking for a big house which to live in." This sentence is grammatically correct but is less commonly used. The use of "which" in this sentence may suggest that you are looking for a specific big house - one that meets your criteria for living in it. It implies that you are not willing to settle for just any big house, but rather one that is suitable for your needs or preferences.

Sentence 4: "I am looking for a big house in which to live." This sentence is also grammatically correct and has a similar meaning to the previous sentences. The use of "in which" emphasizes the idea of living inside the big house and may suggest that you want a house with specific features or qualities.

So, while all the sentences are grammatically correct, they do have slightly different meanings and nuances. The choice of which sentence to use would depend on the specific intention and emphasis you want to convey.