When using "if," it's important to determine whether it introduces a subjunctive or indicative clause. The subjunctive mood is used for hypothetical or improbable scenarios, as in "If I were king." In contrast, the indicative mood is employed when the statement is true or plausible, such as "If I was happy then." This distinction helps clarify the intent and accuracy of the statement.

Additionally, a helpful tip is that if the sentence includes "would" or "wouldn't," the subjunctive mood should be used. For example, "If I were you, I wouldn't take the job" demonstrates this usage. Recognizing these moods can enhance clarity and grammatical accuracy in writing.