Today, I went to the supermarket in a hurry because I wanted to buy something before it starteds to rain. Today, I went to the supermarket in a hurry because I wanted to buy something before it starts to rain.

Alternatively, you can say: "... before it starts raining." While it seems right to say "started" to keep your tenses consistent, the use of the word "before" as a conjunction between your main clause "... I wanted to buy something" and your subordinate clause "... it starts to rain" / "... it starts raining", in addition to using the verb "start"--indicates that the action you were describing is time-dependent. Therefore, it may be independent from your previous tense(s). The use of "... before it started to rain" would only be correct if the rain HAD started WHILE you were going to the supermarket. Since the rain HAD NOT started by then, it only WILL start in the future. The time that you're indicating with "before" and "start" is the present IN the future. In other words, if you are going to describe a future event that is already planned (or in this case, "forecasted") and will be ONGOING, it is more appropriate to use the FUTURE PROGRESSIVE TENSE. Usually, the formula for this tense is "will be + verb-ing" (e.g. "will be running"). But because you used another verb ("start") before "rain" (which can be a verb in context), you would have to answer the question of WHEN it (the rain) "starts" via the appropriate tense, which is the PRESENT in the future. Thus, you conjugate the verb "start" to present tense => "starts" and the verb "rain" to future progressive tense => "raining"

Today, I went to the supermarket in a hurry because I wanted to buy something before it started to raining. Today, I went to the supermarket in a hurry because I wanted to buy something before it started raining.

- "Do you have a list? - My husband asked me" asked my husband. "Do you have a list?" asked my husband.

- "Yes, I only need bread, milk, and rice -," I answered. "Yes, I only need bread, milk, and rice," I answered.

At the checkout, the cashier told me:asked me if I wanted a bag. At the checkout, the cashier asked me if I wanted a bag.

When it's a fairly non-essential line, you can condense your writing to avoid being redundant.

At the checkout, the cashier said told me: At the checkout, the cashier said to me:

- Do you want a bag?

- "No, thank you, I bought one from home -," I answered her proudly. "No, thank you, I bought one from home," I answered her proudly.

- No, thank you, I brought one from home - I answered her proudly. - No, thank you, I brought one from home - I answered proudly.

- No, thank you, I brought one from home - I answered her proudly. - No, thank you, I brought one from home - I answered her proudly.

But when I arrived at thegot to my car, I noticed I had forgotten the most important thing: the soap! But when I got to my car, I noticed I had forgotten the most important thing: the soap!

But when I arrived at the car, I noticed I had forgotten the most important thing:, the soap! But when I arrived at the car, I noticed I had forgotten the most important thing, the soap!