Tone refers to the style or manner of a piece of writing or a speech. Tone helps determine the feel of a work for the audience. The tone can be persuasive or informative, for example. Tone is heavily influenced by other elements such as diction and syntax. The words used and the way they are ordered help an author or speaker convey his tone to the audience.
The attitude of a piece of writing or a speech is closely related to the tone of the piece. The attitude of a piece can be thought of as a broader concept than tone but one that is comprised of the various tones within a piece. For example, an attitude of criticism of a particular topic might be composed of a mixture of negative, persuasive and objective tones that all combine to help convey the overall attitude.
In writing and speaking, diction refers to the choice of words used by the writer or speaker. The vocabulary used in written and oral communication is extremely important; words that objectively mean the same thing can have significantly different subjective connotations for an audience.
Syntax is a concept closely tied to diction. Whereas diction is the choice of words used, syntax is the way those words are structured within a writing or a speech. For example, short, choppy sentences can contribute to a feeling of anticipation and tenseness, while long, flowing sentences can make the reader or listener feel relaxed and calm.