Formal Writing:
* Avoid starting with "IF" unless it's part of a dependent clause: For example:
* "If you want to go, I'll drive you." (This is acceptable as "if you want to go" is a dependent clause that cannot stand alone as a sentence.)
* "If you want to go, then I'll drive you." (This is also acceptable because the sentence continues with an independent clause.)
Informal Writing:
* In informal writing, starting with "IF" is sometimes acceptable: For example, in dialogue or casual writing, it's more common to see sentences beginning with "IF."
Exceptions:
* Emphasis: In some cases, starting a sentence with "IF" can be used for emphasis, particularly in creative writing. This is a stylistic choice and should be used sparingly.
* Questions: It's perfectly acceptable to start a question with "IF." For example: "If you want to go, what time should we leave?"
Overall, it's best to avoid starting sentences with "IF" in formal writing unless it's part of a dependent clause. In informal writing, it's more common to see this construction. Remember, the rules of grammar are not absolute, and there's always room for stylistic variation.