Learn Farsi: شاید امروز باران ببارد.

شاید means "might" or "perhaps". It is an impersonal modal verb, which means it has only one form and never changes, no matter who or what is doing the action. It always requires the main verb of the sentence to be in the subjunctive form.

Why does the verb ببارد start with بـ?

Because of شاید, the main verb must be in the present subjunctive mood. In Farsi, we usually form the present subjunctive by adding the prefix بـ (be-) to the present stem. Here, the verb is باریدن (to rain), the present stem is بار, and the 3rd person singular ending is ـد (-ad). Put it all together and you get ببارد.

The English translation is "It might rain". Where is the word for "it" in the Farsi sentence?

Farsi doesn't use dummy pronouns like "it" for weather. Instead, the weather word itself is the subject doing the action. The literal translation of this sentence is "Maybe today rain rains", where باران (rain) is the noun and ببارد (rains) is the verb.

Does the time word امروز (today) have to go right after شاید?

Time words in Farsi are flexible but generally belong near the beginning of the sentence. Placing امروز right after شاید is very natural, but you could also put it at the very beginning (امروز شاید باران ببارد). Just remember that the verb ببارد always stays at the end of the sentence.