Very interesting question – it actually is proposed that we actually don’t think in language, we think actually think in images and then subconciously verbalise it! We couldn’t say for sure yet if this is true!
People Deaf from birth tend to think in sign language or their native language (with which they read)
there s a very interesting study that tested people with double mother tongue (with parents from different countries). They observed that depending on the language they were interviewed in, they pictured different images or were able to answer the questions faster or slower.
For example a japanese/english will think of time as horizontal line if you refer to it in english but he will think of time as a vertical line if you refer to it in japanese, as japanese write vertically.
I found this question really interesting, I don’t really know the answer but thought I would share my thoughts whichy are when I think about it maybe we do see pictures in our minds, but my thoughts seem to be in words but dreams are more picture orientated.