If you mean what sentence in the paragraph contains the main idea then it would be the topic sentence and the rephrased version of the conclusion.
When looking for the main idea in a single paragraph, I would focus on identifying the central topic or theme that the paragraph is discussing. This can usually be found in the topic sentence or repeated throughout the paragraph. It is important to distinguish the main idea from supporting details or examples.
The topic sentence summarizes the main idea of a paragraph and supports the thesis.
if a paragraph does not have a topic sentence then
simple sentence with the main idea.
Topic sentence
a topic sentence
The topic sentence or thesis statement gives you the main idea of the paragraph. If you are not sure what the main idea is, read the paragraph again and look at each sentence. See if that is the sentence which all the other sentences support by turning it into a question and see if the other sentences answer that question.The topic sentence is usually the first sentence of the paragraph. It makes a statement about a topic and the rest of the paragraph explains the topic sentence or gives examples of the topic sentence.
Implied Main Ideas sometimes,there is no topic sentence in a paragraph. this does not mean,that there is no main idea. (implied) (:-)
The sentence that introduces the paragraph's main ideaa sentence that introduces the subject of the paragraph.
It restates the main idea of the paragraph using different words.
Topic Sentence
The topic sentence should state the main idea that will be developed. The reader should easily be able to see the main idea, simply by reading the topic sentence. The topic sentence is usually the first sentence in the paragraph, and is the most important thought in the paragraph.