the three types of sentences are:
topic
Good topic sentences have two parts:
Notice that this sentence (My senior year of high school was challenging.) does not state a fact; rather, it states an idea which needs support. It leaves the writer with something to say; it leaves the reader wanting to know more (How? What were the challenges?). Factual statements, on the other hand, do not make good topic sentences. If the sentence read, "I graduated from Wilson High School in 1995," the writer would have little more to say because that statement does not require support.
The topic sentence should serve as an anchor for the rest of the paragraph. In the above example, the writer should not stray from the idea of challenges. It may be tempting to throw in the fact that s/he was on the honor roll the entire year, but if it can not be related to the topic sentence (perhaps by linking it because studying hard enough to keep good grades was a challenge), it should not be included in the paragraph.
support
Support sentences must be directly linked to the topic sentence of the paragraph. When the sentences in a paragraph are not consistent with the main idea provided by the topic sentence, the paragraph lacks unity (one of those mysterious English-teacher words!). Every sentence in the paragraph should relate to the main idea.
Support sentences should be arranged in logical order and connected by transitions to provide coherence (that other one!). Arrangement of support sentences might be based on importance (usually least to most), time (usually first to last), or even space (far to near, near to far) -- just about anything, as long as it serves the writer's purpose. Transition words are often used improve coherence and to reinforce the order in which supporting points are presented. Sometimes writers use simple transitions such as these to connect support sentences:
These sentences not only use transition words (first, second, final), but also repeat the key word challenge. This repetition of key words helps the reader keep in mind the main idea of the paragraph.
Since support sentences can be somewhat general, they usually require the proof provided by detail/example sentences.
detail/example
In the hierarchy among sentences in a well developed paragraph, detail/example sentences are at the bottom. However, that does not mean they are the least important. In fact, detail/example sentences, if you look back at the pyramid, are the very foundation of the paragraph -- a foundation upon which the support sentences and, ultimately, the topic sentence rest.
It is not enough to say, "My first challenge at Wilson High School was studying enough to make good grades and stay on the honor roll." This statement may support the main idea of the paragraph, but the statement still needs to be proven. How much was enough? Why was it a challenge? Can the writer give convincing details or examples to prove it?
Consider this example:
[topic sentence] My senior year of high school was challenging. [support sentence] My first challenge at Wilson High School was studying enough to make good grades and stay on the honor roll. [detail/example] I often studied past midnight, even though I had to get up at 6:00 a.m. to be ready in time to catch the school bus. [detail/example] When I was studying for my chemistry mid-term in Ms. Beasley's class, I never went to bed at all -- but I made an "A" on the exam!
Although this paragraph is unfinished, you can see how important the details are to its development. Without them, the supporting points do not really mean much; they do not seem as real or immediate to the reader. Notice the use of names, specific times, and concrete details. You may have good ideas without providing the detail to support them, but your goal is to convince your reader. Good use of details and examples will help you get your main idea across.
Declarative - Declares something, provides information - I have a dog.
Interrogative - a question - Who are you?
Imperative - a command - Make the bed.
Exclamatory - ends in an exclamation point - We won!