Guide
Paragraph structure and topic sentences
Paragraph structure is the internal organisation of a paragraph around a single controlling idea — usually opened by a topic sentence and developed with evidence and explanation.
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The topic sentence: one idea per paragraph
A paragraph is the unit that develops a single idea, and the topic sentence is the sentence that states that idea — usually the first sentence. It works like a miniature thesis for the paragraph: it makes a claim, and everything that follows supports, explains or illustrates it. The principle behind this is unity: every sentence in the paragraph should relate to the topic sentence, and anything that does not belongs in a different paragraph or should be cut. A clear topic sentence also helps the reader skim, because the opening lines of successive paragraphs trace the spine of the argument.
PEEL and MEAL: developing the idea
Two widely taught models give paragraphs a dependable shape. PEEL stands for Point, Evidence, Explanation, Link: state the point, give supporting evidence, explain how that evidence supports the point, then link forward to the next paragraph or back to the thesis. MEAL — Main idea, Evidence, Analysis, Link — is the close North American equivalent, emphasising analysis as the step where you interpret the evidence rather than merely presenting it. Both guard against the most common paragraph fault: dropping in a quotation or statistic without explaining what it shows. The explanation or analysis step is where the thinking happens, and it is usually the longest part of the paragraph.
Unity and coherence
Two qualities make a paragraph hold together. Unity means it sticks to one idea — the one named in the topic sentence — so the reader is never asked to track two arguments at once. Coherence means the sentences flow logically, each following sensibly from the last, so the paragraph reads as a connected line of reasoning rather than a list. Coherence is supported by consistent subjects, deliberate repetition of key terms, and pronouns that refer clearly back to what came before. A paragraph can be grammatically correct yet incoherent if its sentences do not connect; building in these links is what turns separate sentences into an argument.
Transitions between paragraphs
Cohesion across paragraphs is what makes a whole paper read smoothly. Transitions are the words, phrases and sentences that signal how one paragraph relates to the next — adding (furthermore, in addition), contrasting (however, by contrast), showing cause (therefore, as a result), or sequencing (first, subsequently). The strongest transitions do more than label the relationship; they carry an idea from the previous paragraph into the next, so the link feels earned rather than bolted on. Used well, transitions turn a series of self-contained paragraphs into a continuous argument, guiding the reader from point to point without jolts.
Key facts
At a glance
- Topic sentence: states the paragraph’s single main idea, usually first
- PEEL: Point, Evidence, Explanation, Link
- MEAL: Main idea, Evidence, Analysis, Link
- Unity: every sentence supports the topic sentence
- Coherence: sentences follow logically and connect clearly
- Transitions: signal how each paragraph relates to the next
Common questions
FAQ
What is a topic sentence?+
A topic sentence is the sentence — normally the first in a paragraph — that states the paragraph’s single main idea. It acts as a mini-thesis: it makes a claim, and the rest of the paragraph supports, explains or illustrates that claim. Clear topic sentences let a reader follow the argument by skimming the opening line of each paragraph.
What is the PEEL paragraph structure?+
PEEL is a model for building body paragraphs: Point (state the main idea), Evidence (provide support such as a quotation, data or example), Explanation (show how the evidence supports the point), and Link (connect back to the thesis or forward to the next paragraph). It ensures every paragraph both presents evidence and explains its significance.
How long should a paragraph be?+
There is no fixed length, but a paragraph should be long enough to develop one idea fully and short enough to stay focused on it — often three to eight sentences in academic prose. The real test is unity: when you move to a genuinely new idea, start a new paragraph, regardless of word count.
Going deeper
