Okay: - special -> is something that is better than other things. e.g a birthday is special compared to an ordinary day. A really good cake is special in comparison to a regular sponge. An iced doughnut with jam is special in comparison to a plain, glazed doughnut. i.e. it is out-of-the-ordinary in a good way. - particular -> can refer several, related, concepts, but has the idea that one thing has characteristics that make it stand out in some way. Or you can refer to 'this particular one' rather than another one. It's a way of indicating a selection from a set. - peculiar -> A thing has characteristics that makes it stand out in a strange or unusual way. e.g. food might have a peculiar taste if it tastes a bit odd. Or if someone is behaving strangely then they might be referred to as 'being peculiar'. - especial -> I don't think this is English! (possibly, Spanish?) - specific -> This is a way of indicating one item from a set of items. e.g. this specific one, rather than that one (when pointing at something), or saying 'the specific thing I want to talk about is ...' So, bringing them all together: "It was a very special day, because a particular person I was interested in came. However, when she ate the fish she looked very peculiar and then I remembered that she had specifically said she was allergic to cod."

Here is the definition of "especial" in the Oxford Dictionary: "Better or greater than usual;special. Example: these traditions are of especial interest to feminists."