* "The sun is shining." This sentence states a fact.
* "I think it's going to rain." This sentence expresses an opinion.
* "She went to the store." This sentence describes a past event.
The indicative mood contrasts with the other verb moods like the imperative (giving a command, e.g., "Go to the store!") or the subjunctive (expressing a wish, e.g., "I wish I could fly").
In essence, if you're simply stating something as a fact or an opinion, you're using the indicative mood.