When you learn shorthand, you can focus on what you have to write down. So, concentration will be enhanced. Your listening ablility will be increased. You can do work more effectively. When you listen to lectures, you can summarize what the speakers say. So you can be a good hearer. The disadavantages are as follows. You have to translate shorthand into English again if you want to use what you have written in shorthand. It takes time to do so.

You will need many notebooks or workbooks to practice shorthand. Then you have to pay more money. You need to use many writing materials to be a good stenographer. If you use a special keyborad for shorthand, you have to pay money for that, though you can type fast by computer shorthand. Have a good day! (There would be some incorrect expressions. You can get information on the Internet using google.)
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I made a composition. Would you like to correct any errors?

When you learn shorthand, you must focus on what you have to write down, so concentration will be enhanced. Your listening ability will be increased, and you can do work more effectively. When you listen to lectures, you can summarize what the speakers say, so you can be a good listener. The disadvantages are as follows. You have to translate shorthand into English again if you want to use what you have written in shorthand. It takes time to do so. You will need many notebooks or workbooks to practice shorthand. Then you have to pay more money.<~~This sentence doesn't seem to fit; how can you connect this idea to the sentences around it? You need to use many writing materials to be a good stenographer. If you use a special keyboard for shorthand, you have to pay money for that, though you can type fast by computer shorthand. Have a good day! (There would be some incorrect expressions. You can get information on the Internet using Google.)

I have corrected some spelling errors, and I have connected some sentences so that you don't begin any sentence with a coordinating conjunction (and, or, but, nor, for, so, yet).

Let me know if you have any questions about this.

"and you can do work" ~~> would be better phrased as one of these:

... and you can do more work ...

... and you can work ...

Your composition is well-written, but there are a few minor errors that I can help you correct. Here's the revised version:

"When you learn shorthand, you can improve your concentration as it allows you to focus on what you need to write down. Your listening ability will also be enhanced, making you a more effective worker. Moreover, during lectures, you can summarize the speaker's points, which makes you a skilled listener.

However, there are some disadvantages to learning shorthand. If you want to use what you have written in shorthand, you will need to translate it back into English, which can be time-consuming. Additionally, practicing shorthand requires many notebooks or workbooks, leading to increased costs. Furthermore, becoming a proficient stenographer necessitates the use of various writing materials. If you choose to use a special shorthand keyboard, you will need to invest money, even though using computer shorthand allows for fast typing.

If you encounter any incorrect expressions, I recommend using Google or other online resources to find accurate information. Hope you have a great day!"

In this revised version, I corrected some wording, punctuation, and added a concluding sentence. Remember, it's always a good idea to proofread your writing for any potential mistakes before submitting it.