When is it easiest to learn a language, such as Spanish?
Well, it appears that at a formative age children are most able to learn languages and skills. Their mind is like a "sponge" at this stage and they are very receptive to what is going on around them. However, it is not impossible to learn a language such as Spanish later on. It just might be more difficult.
How does one learn how to write?
Through the use of practice and guidance (a child normally) begins to learn how to use their writing utensil to make the shapes of the letters or numbers, etc. Normally, this is done through muscle memory as the learner's mind learns how to create the shapes or lines that form words, and from this others can read what is spelled out.
Is English but a language, or is it more than that?
English can be thought of as not only a language, but it can also be thought of as dealing with England or The United Kingdom. There is the term "Englishman."