Topic Sentence Generator
Turn a paragraph subject and controlling idea into several topic sentence patterns (more when you add a reason or a concession), then score your own sentence against seven checks.
About this tool
Topic Sentence Generator
Turn a paragraph subject and controlling idea into several topic sentence patterns (more when you add a reason or a concession), then score your own sentence against seven checks.
A topic sentence generator builds the opening sentence of a body paragraph from its two obligatory parts: the subject the paragraph is about, and the controlling idea — the arguable claim the rest of the paragraph will prove. Give it both and it produces the standard composition patterns, from claim-first to the concessive although-pivot, and adapts the wording to whether this is the first, middle or last body paragraph. A separate checker scores a sentence you have already written against seven things markers look for, including length, single-sentence form, and whether the sentence announces the paragraph instead of making a claim.
How to use Topic Sentence Generator
- 1
Open Topic Sentence Generator on AltFTool — it loads instantly in your browser.
- 2
Type the subject the paragraph is about and the controlling idea you claim about it.
- 3
Add an optional supporting reason or objection to concede, and say where this paragraph sits, to unlock the concessive shape.
- 4
Pick a pattern, press "Send to the checker below" to score it, then press Copy sentences.
Why use Topic Sentence Generator
Subject plus controlling idea
Forces the two parts a topic sentence must have, so it cannot come out as a bare topic.
Position-aware wording
Middle paragraphs get a linking opener; the last one gets an emphatic shape.
Seven-point checker
Scores your own sentence on length, form, filler, evidence placement and announcement phrasing.
Common use cases
- Turn a bullet point from an essay plan into an opening sentence that actually commits to a position.
- Fix a paragraph that starts with 'In this paragraph I will discuss…' by moving straight to the claim.
- Vary the sentence shape across four body paragraphs so they do not all open the same way.
- Check a sentence before submission for the usual faults: two sentences fused together, a citation crowding the claim, or filler like 'many aspects'.
Frequently asked questions
What is a topic sentence?
It is the sentence that states a paragraph's single main idea, and it has two parts: a subject and a controlling idea. "School uniforms" is a subject; "school uniforms hide income differences without removing them" adds the controlling idea and gives the paragraph something to prove.
How long should a topic sentence be?
Roughly 8 to 30 words. Shorter than eight and it rarely carries both a subject and a claim; longer than thirty and it has begun doing the evidence's work, which belongs in the sentences that follow.
Should a topic sentence contain a quotation or citation?
No. The topic sentence makes the claim in your own words, and the quotation, data or citation that supports it comes in the next sentences. A quotation in the opening line makes the paragraph look like it is reporting a source rather than arguing a point.
Does a topic sentence always go first in a paragraph?
Usually, and always in timed or exam writing, because it tells the marker immediately what the paragraph is doing. Experienced writers sometimes delay it for effect, but a delayed topic sentence only works when the paragraph is short enough for the reader to hold the evidence until the claim arrives.