It really depends on how you look at it. But 'underneath' and 'beneath' are actually more formal literary words. They imply something being 'under', but it's covered. . .and 'below' implies something is lower than another, not necessarily being under something. Sorry if it doesn't make too much sense the way I typed it.

The prepositions 'under' and 'underneath' are fairly very close in meaning. 'Under' is used more in informal and spoken contexts, but they are often interchangeable. One important difference is that 'underneath' can also be an adverb. This means that you can use it on its own, not followed by an noun. For example: 'My brother put his signature on the form and I put mine under/underneath it.' 'My brother put his signature on the form and I put mine underneath.' As for 'beneath', I wouldn't worry about it. It is fairly formal and old-fashioned. The only time you might have to use it is in certain set phrases such as 'Beneath contempt'. 'Below' has a different meaning from 'under'. It means 'at a lower level'. For example, we use it with temperatures - 'The temperature often drops below zero' and ages 'They aren't allowed to marry because they are below the legal age of consent'. If two objects are touching, you can say that one is under the other. You cannot use 'below' in this way. For example, if you have a pile of books, you can say that the red book is under (or underneath) the blue book. You cannot use 'below' here. But if you have two pictures hanging on the wall, one above the other, you might say that the blue picture is below the the red one ( or that the red one is above the blue one). Here, we can use 'below' and its opposite 'above', because we are talking about comparative levels. But note that you could also use 'under' instead of 'below' in this situation, and the meaning would be the same. Here's a useful tip - if you're not sure, just use UNDER. Given a choice between these four words, 'under' will always be right, whereas the others could be wrong. I hope that solves your problem!