Speaking a second language will change your life.
Speaking a second language fluently makes a significant change in your life. Firstly, speaking a second language with fluency gains you an extensive field of knowledge. Undoubtedly, when you do not understand the lessons, you can convey your idea to your professor. Besides, you can make a video call or have a face-to-face conversation with foreigners to share information. Secondly, it is clear that you will have a brilliant career when speaking like a native communicator. If a Mexican partner suddenly appears in your company, nobody but you can communicate with him, you will surely get a chance to climb the career ladder. For example, Jack Ma learnt English to change his life and he is a billionaire now. Thirdly, talking like a native speaker helps you have a new viewpoint to the world. You can make friends with foreigners, learn about other cultures, have trips to some countries which speak your second language without any hesistancy. In conclusion, it is needless to say that speaking a second language fluently makes your life better and brighter. Not only does it help you improve your knowledge, have a close relationship with foreigners but you also have a promising career.
1. In line one,be sure to answer what kind of knowledge you are referring to. Be specific!
2. In line two, I have no idea what you're talking about. What lessons? What ideas? What is the connection between professor and language?
3. The sentence following the the professor one in line two likely ties to it, but one cannot be too sure...
4. In line three, when you refer to a Mexican partner, I suggest saying a Spanish speaker since it's more specific because a Mexican partner doesn't answer your prompt. And be sure to include why nobody can communicate with him.
5. Line four, Who is Jack Ma? Explain who this is. Also, how did English change his life? Give a little context perhaps.
6. Line five, when you refer to a new viewpoint, I suggest changing the keyword "have" into understanding a new bla bla...
7. Line six, change the word "which" to that. Which sounds weird.
8. Jumping back to line five, after "world" you could put a ":" <- whatever that's called, then put semi colons in place of each comma. Here, " Thirdly, talking like a native speaker helps you understand a new viewpoint to the world : You can make friends with foreigners; learn about other cultures; have trips to some countries which speak your second language without any hesitancy." Just makes it look fancier without going overboard :D.
I'm not sure what your word limit is on your prompt, but if there is at least a 500 word limit, then I suggest separating this into paragraphs because each point you made could be explained more thoroughly so your reader has a full understanding.
Overall, just be clear what you're talking about. As is, it looks like you're jumping all over the place.