What a grammar checker can—and cannot—do
A grammar checker is a fast second reader for emails, essays, articles, applications, and everyday writing. It can catch misspellings, missing punctuation, subject–verb disagreement, sentence fragments, and run-on sentences that are easy to overlook after several revisions. Deeper editing can also smooth awkward phrasing or make a sentence easier to follow.
It cannot know your intention as well as you do. A grammatically tidy sentence can still use the wrong name, date, fact, quotation, or tone. Specialized terms, dialogue, dialect, and deliberate fragments may also be “corrected” when they should stay. Treat every suggestion as a proposal, especially in creative, technical, legal, or academic work.
Choose the right edit depth
Fix Grammar is the conservative option for spelling and punctuation. Proofread, the default, repairs errors while trying to preserve your wording and voice. Improve can change clarity, flow, and word choice, so it is useful for a nearly finished draft that still feels rough. Rewrite allows substantial rephrasing for impact; use it when you want a new expression of the same idea, not just a cleanup.
Start lighter than you think you need. If the text is already close, a heavy rewrite can erase useful nuance or make every sentence sound equally polished. You can always run a short passage again at a deeper setting after reviewing the first pass.
Review corrections like an editor
Read the changed sentence in context, not only the highlighted words. Check that pronouns still point to the right noun, the tense remains consistent, and the replacement keeps your level of formality. Read important passages aloud; your ear often catches repetition, stiff rhythm, or a change that is technically correct but unnatural.
The changes view marks removals in red and additions in green. When a revision is extensive, the tool automatically opens the cleaner corrected-only view so the markup does not become overwhelming. You can switch views at any time, copy the corrected version, or choose Apply all to place it back in the input box for another pass. Because the result is plain text, save your original document and expect to restore headings, italics, links, or other formatting after pasting it back.
For a long document, check one section at a time. Smaller passages make it easier to judge each suggestion, protect transitions between ideas, and spot places where a correction accidentally changes your meaning.