When used by themselves they mean "probably never" and "probably nothing". "If the sun stopped shining, there wouldn't be much we could do to survive, if anything." = "If the sun stopped shining, there wouldn't be much we could do to survive, [but probably nothing we could do could help us]." "He's so profoundly lazy he rarely leaves his bed, if ever." = "He's so profoundly lazy he rarely leaves his bed, [but probably never does]" Other phrases this works with: "if any" -> "probably none" "if anybody" -> "probably nobody"

It`s difficult to take these phrases out of context and see how they are used, but this is the best that comes to mind. „If ever“ is a term that tends to pop up at the end of a sentence, preceded by a comma, and is frequently contrasted with words preceding it meaning rarely. Like the above example, „He rarely gets out of bed, if ever.“ The „if ever“ adds the possibility that something mentioned never happens at all, when paired with rarely. „Rarely is that done, if ever.“ Something here is done only on rare occasions, or never. „Doctors rarely treat this disease with surgery, if ever.“ Doctors only on rare occasions use surgery to treat a particular ailment, but ordinarily never do. „If ever“ tends to be contrasted with „ rarely“ relatively frequently. So, look for these kinds of word pairings. „If anything“ is paired with expressions involving the minimal quantity of something, or perhaps its non-existence. It always helps to see the expression in a context to understand it. As an example, I could say „that guy has probably only got a couple of dollars in his pocket, if anything.“ See how „if anything“ is paired with a description of something meaning „very little“ or „not much“? „That person is so poor, I`d bet he has very little money in his bank account, if anything.“ Another example which illustrates how the phrase is used with „if anything“. Think of a preceding description of somebody not having much of quantity or value, then to toss in the idea that this minimal quantity or value could be zero, use „if anything“ to suggest this. This phrase normally comes at the end of a sentence, and is preceded by a comma.

If anything is like „if at all“, which is synonymous. It`s a bit hard to get a good translation for and is one of these phrases you could get away with by just not even translating it. So, it really doesn`t mean that much or add too much to a sentence. It´s like a German expression, „wenn überhaupt“, sort of like „if any“ „if at all,“ „if indeed“, If you can understand those expressions they are all pretty much the same.

The expression that a performance was great „if ever there was one“ seems more idiomatic to me than anything else, and I can only describe it as a deviation from the more typical use of the phrase. I`d definitely add it to my list of possible uses of the phrase, but just keep it separate from the more common uses. The phrase „if anything he looks younger“ is fine, but it seems to lack context standing alone. It might come up in a sentence like this, „I don’t think he looks older than the last time we saw him. If anything he looks younger.“ In this context, it means „on the contrary.“ That I wouldn’t call an idiomatic use of the term, just a variation from another use of it. These phrases can have multiple applications and, instead of trying to find a rationale for why they are used as they are (there might not be one), I`d just acquaint myself with a few examples of how they are used and then just move on.

Hi Luiz, If ever is used for emphasizing that a particular description is exactly right for someone or something: For example: -It was a brilliant performance if ever there was one. If anything is used for saying how someone or something is different when you are not sure whether there really is any change or difference: For example: -if anything he looks younger and fitter than he did before. Hope it helps!