Questions & Answers about Я часто думаю о погоде.
Why is the preposition о used here instead of об?
We use о before words that start with a consonant sound, like the п in погоде. You only use об when the following word starts with a vowel sound (like а, о, у, э, or и) to make it easier to pronounce.
Why does the word for weather change to погоде instead of its normal form погода?
The preposition о (meaning "about") requires the noun that follows it to be in the Prepositional case. For most feminine nouns ending in -а like погода, you form this case by changing the -а to an -е.
Why does the verb думаю end in -ю here?
This is the present tense conjugation for я (I). The dictionary form of the verb is думать (to think). To say "I think", you drop the -ть ending and add -ю.
Does я думаю mean "I think" or "I am thinking"?
It can mean both! Russian does not have a separate continuous tense like English does. Я думаю translates to "I think" (a general habit, like in this sentence) or "I am thinking" (happening right now), depending entirely on the context.