"Therefore" is a conjunctive adverb that you can use as a transition word in sentences and paragraphs. This adverb shows the cause and effect between independent sentences, for this reason, it cannot be used when starting a paragraph or forming part of an independent sentence. If you would like to use "therefore" at the time of writing, there are a number of things you need to take into account to ensure that you use it correctly. There are also repeated misuses of "therefore" that you will want to avoid.
Steps
Method 1 of 3: Finding Common Uses for "Therefore"

Step 1. Use "therefore" to show cause and effect
"Therefore" will not work in all sentences. It has a very specific meaning and is only appropriate to use in certain situations. The best way to remember when it is appropriate to use "therefore" in a sentence is to consider whether you are using it to show cause and effect. In other words, does the first segment lead to or cause the next segment? Otherwise, "therefore" would not be appropriate for that sentence.
- For example, use "therefore" to represent the cause and effect relationship between these two segments: "John studied hard for the test. He got an A +." Your final sentence would be "John studied hard for the test. Therefore, he got an A +."
- Another example would be, "People who exercise are in better health. You should exercise." Adding "therefore" would improve the transition between these two ideas. "People who exercise are in better health. Therefore, you should exercise."

Step 2. Replace the transition words and phrases of parallel meanings with "therefore."
"Therefore" can be used to replace other words or phrases, but it is important to check their meaning first. Not all transition words or phrases can use "therefore."
- For example, "Sally passed the driving test. As a result, she received her driver's license." You can replace "as a result" with "therefore" because they have the same meaning in this sentence.
- Don't use "therefore" in place of a coordinating conjunction in most cases. Coordinating conjunctions include the words for, and, nor, but, or, yet, and so. Each of these terms has a specific meaning and they are not interchangeable with each other or with "therefore". Always check the meaning of a word or phrase before using it in a sentence.

Step 3. Include "therefore" to improve sentence fluency
Including "therefore" at the time of writing is a good way to improve the fluency of your text. It may appear that a sentence or paragraph is missing something, but adding a transition word such as "therefore" can fill in that gap. Try reading your work aloud to find the spaces where you may need a transition word and then see if "therefore" could be used in that case.
For example, something seems to be missing from these sentences: "The weather was hot. He wore shorts and a T-shirt to school." However, adding a transitional word like "therefore" improves fluency: "The weather was hot. Therefore, he wore shorts and a T-shirt to school."
Method 2 of 3: Use appropriate punctuation and capitalization for "therefore"

Step 1. After "therefore" put a comma
"Therefore" must always be followed by a comma. This is because there is a natural pause after "therefore" when it is part of a sentence. Without the comma, the sentence can sound very fast to readers.
- For example, "I like spending time in nature. Therefore, I go camping every summer." Without the comma, there is no pause after "therefore". However, if you add the comma, this will mean that readers must pause after the word "therefore".
- The final sentence should read like this: "I like spending time in nature. So (pause) I go camping every summer."

Step 2. Place a semicolon (;) before "therefore" when separating two independent sentences
If you are using "therefore" in the middle of a sentence to separate 2 independent sentences, then you will need to use a semicolon. In other words, if each part of the sentence could be separated as a single sentence, then put a semicolon at the end of the first independent sentence, followed by "therefore," a comma and the next sentence.
For example, "Marcus loves to travel with his family, therefore he is constantly on the lookout for low-cost airfare."

Step 3. Capitalize when "therefore" is at the beginning of a sentence
Like any sentence, "therefore" should start with a capital letter only if it is at the beginning of a sentence and not anywhere else.
Method 3 of 3: Avoid Common Mistakes

Step 1. Separate independent sentences by using "therefore"
You can use "therefore" in the middle of a sentence that includes 2 independent sentences, but not in a sentence that includes dependent sentences. An independent sentence can be kept alone as a sentence, or you can separate independent sentences by using a semicolon.
- For example, "therefore" can be used to separate 2 sentences such as "California is a coastal state. It has many beaches." You should write it like this: "California is a coastal state, so it has a lot of beaches."
- In some cases, you can use "therefore" to start a sentence. For example, "June's car broke down on the way to work. Therefore, she was late for the meeting."
- Remember that "therefore" needs to be in the middle of 2 independent sentences and not after them.

Step 2. Use "therefore" sparingly
"Therefore" is not a word that should be used very often in writing. It would sound better if you use it in moderation to avoid overuse. Use other transition words to vary the sentences, such as "then", "then", "consequently", "consequently", "because of it" or "since".
- For example, you could replace "therefore" with "for it" in the previous example. The sentence would be: "California is a coastal state, so it has many beaches."
- Remember to always make sure that the other word you use works the same as "therefore" in the sentence. If you are not sure, look up what it means is a site like this

Step 3. Write "therefore" instead of saying it
"Therefore" is not used much when speaking than when compared to writing because it can sound very formal for a casual conversation. For this reason, avoid using "therefore" when speaking in most cases, and go for a more casual transition such as "then" and "later."
- For example, it might sound a bit weird to others if you say "It was raining when I left for work this morning, so I needed my raincoat."
- An exception to this rule would be if you were giving a speech or presentation.