Here's why:
* Emphasis: Placing "honestly" at the beginning can emphasize the truthfulness of what you're about to say. For example: "Honestly, I'm not sure what to do."
* Informal vs. Formal: While it works in some contexts, "Honestly" can sound more informal. In more formal writing, you might use a different phrase like "To be frank," or "In all honesty."
* Sentence Structure: It's crucial to ensure the sentence structure is grammatically correct. You'll likely need a comma after "Honestly" if it's at the beginning.
Examples:
* Informal: "Honestly, I think that's a terrible idea."
* Formal: "In all honesty, I find it difficult to agree with your proposal."
Overall: It depends on the context and desired tone. If you're unsure, consider rephrasing to avoid a potentially awkward sentence.