Hello there, English learner! 👋
Great question about “so” versus “therefore.” These two words are both used to show cause and effect, but they differ in tone, formality, and sentence structure. Let’s break it down clearly so you know when and how to use each one correctly.

🗝️ Quick Summary

Both words show results or consequences, but the way you use them in a sentence is different. Let’s look at each one more closely.

📚 1. So – Informal and Conversational

✅ Meaning:

“So” connects two clauses and shows that one thing happened as a result of another.

🧠 Think:

➡️ Cause ➡️ so ➡️ Effect

🗣️ Examples:

• It was raining, so we stayed inside.
• I was hungry, so I made a sandwich.
• She didn’t study, so she failed the test.

🧾 Structure:

[Cause] + so + [result]

👉 “So” is used like “and” or **“but”—to join two ideas into one sentence.
👉 It’s not usually used at the beginning of a sentence in formal writing.

📚 2. Therefore – Formal and Written

✅ Meaning:

“Therefore” is a transition word that means “as a result,” “because of that.”

🧠 Think:

➡️ Logical conclusion or result
➡️ Common in essays, reports, and formal speech

🗣️ Examples:

• He broke the rules. Therefore, he was punished.
• Prices went up; therefore, fewer people could afford it.
• The data was flawed. Therefore, the results are unreliable.

🧾 Structure Options:

1. Two sentences:

[Statement]. Therefore, [result].
The road was icy. Therefore, we canceled the trip.

1. With a semicolon (formal):

[Statement]; therefore, [result].
The machine failed; therefore, the experiment was postponed.

👉 Avoid using “therefore” to start a sentence in casual conversation—it sounds too formal.

🔁 Side-by-Side Comparison

📝 Practice Time: Fill in with so or therefore

1. It was late, ______ we took a taxi.
2. He forgot his umbrella. ______, he got wet.
3. The service was terrible, ______ we left no tip.
4. She was sick; ______, she didn’t attend the meeting.
5. I didn’t understand the instructions, ______ I made a mistake.

✅ Answers:

1. so
2. therefore
3. so
4. therefore
5. so

💡 Learning Tip:

Pro Tip:

• Use “so” in everyday speech and writing.
• Use “therefore” when writing essays, formal reports, or giving presentations.

🎯 If it sounds like something you’d say in a friendly chat, go with “so.” If it sounds like something from a business meeting or academic paper, go with “therefore.”