Topic Sentence Writing Exercises: Level B1-B2 (with Answers)

A strong topic sentence must clearly state the paragraph's main idea and include a controlling idea. 'Eating a variety of fruits and vegetables can significantly reduce the risk of chronic diseases' does both effectively, specifying the topic and the controlling idea of disease reduction.

While a topic sentence commonly appears at the beginning of a paragraph, especially in formal writing, this is not a strict rule. It can sometimes appear in the middle or even at the end of a paragraph.

'Public transport should be made free because it would reduce traffic congestion and lower pollution levels' is the most effective topic sentence because it clearly states a main idea (free public transport) and includes a controlling idea (reducing congestion and pollution) that the rest of the paragraph can develop.

A topic sentence summarises a paragraph's main point. A controlling idea directs where the paragraph will go. A thesis statement presents the essay's central argument. Supporting sentences provide evidence or detail for the topic sentence.

Paragraph C has a topic sentence about swimming as exercise, but the second sentence discusses a cousin's wedding, which is completely unrelated. All supporting sentences must relate back to the topic sentence.

'Furthermore' is the best transition to use here because it adds supporting evidence to the topic sentence. 'However' signals contrast, 'Nevertheless' signals concession, and 'On the other hand' introduces an opposing point — none of which fit the context of adding more supporting detail.

The original sentence is incomplete — it lacks a predicate that finishes the thought. 'There are many reasons why renewable energy is essential for the future' completes the sentence with a clear topic and controlling idea.

A well-structured paragraph begins with a topic sentence that states the main idea, followed by an explanation of that idea, then specific evidence to support it, and finally a concluding sentence that ties the paragraph together.

'Increased government investment in public healthcare would ensure that all citizens have access to essential medical services' is the most appropriate because it clearly states the paragraph's position and includes a controlling idea (access to essential services) that can be developed with supporting evidence. The other options are too vague, too informal, or function as a thesis rather than a topic sentence.

A thesis statement presents the central argument of the entire essay, while a topic sentence introduces the main idea of a single paragraph. The topic sentence should relate back to the thesis statement but is more specific in scope.

'Social media has a significant impact on teenagers' self-esteem due to constant exposure to unrealistic standards' uses formal, precise language appropriate for academic writing. It includes a clear topic and controlling idea. The other options are too casual, too vague, or use inappropriate register for academic writing.

A topic sentence should be clear enough to let the reader know the paragraph's main idea, but it should not reveal every detail. It needs to leave room for the supporting sentences to expand, explain, and provide evidence.

This topic sentence serves a dual purpose: it transitions from the previous paragraph's discussion of causes while introducing the new paragraph's focus on health consequences. This creates a smooth logical flow between paragraphs in the essay.

'Access to quality education is the most effective way to reduce income inequality in developing nations' is the strongest improvement because it transforms a vague, unfocused sentence into one with a clear, specific topic and a controlling idea that can be developed throughout the paragraph.