Here are a few examples that I took from my own personal statement (the introduction part only):
“What makes teaching a second or foreign language is different from teaching another subject? The answer may lie in the objective of the teaching-learning process itself: the learners should be able to acquire the second or foreign language well. Thus, ...”
“The connection between language and culture has always been one of my greatest interests. Language, as Agar (1994) describes it, constructs a world of meanings. The discourse of language goes beyond what words and sentences could explain – and there we can find culture, in which individuals are aware of differences. Language occupies the gap between individuals with sound while culture shapes the connection between humans through meanings (Agar: 1994 cited in Risager: 2006).”
In the introduction part, you could show your interest in the field of study and also your understanding about the study.
2nd paragraph: your past. Here you can explain your relevant experience that is strongly related to the proposed field of study. It is indeed a strong point if your background (educational and professional) matches the study.
“When I began my undergraduate career, ...”
“My five year experience in teaching a foreign language (English to Indonesian students and Indonesian language to foreign students) allows me to …”
3rd paragraph: The next paragraph could be similar to the previous one. You may want to explain your recent professional experience, your role and the current projects you have accomplished that, again, reflects your capability in the proposed field of study.
4th paragraph: the future. The next paragraph could be the right place to explain why the programme and the university you have chosen is the best one to pursue your education. Again, please avoid cliche statement (visit https://www.kent.ac.uk/careers/postgradmenu.htm#AppsInts). Show that you have done some research about the programme and the university and the courses nicely fit your interest. Here you may also show that you have read some of the professors’ papers and even you have contact them.
“Furthermore, doing a PhD in Educational Linguistics at The University of Pennsylvania, Graduate School of Education will equip me with more proficiency in this area. The core courses offered (Sociolinguistics in Education, Language Diversity and Education, Second Language Development and Language Policy and Planning) correspond to my research interest. The standing faculty of this program would provide excellent supervision. I was thrilled to learn that Professor Nancy H. Hornberger was one of the faculty. Professor Hornberger’s Encyclopedia of Language and Education has helped me gain a better understanding of language education policy and some aspects which greatly influence this, such as culture, gender, class, pluralism and moral dimensions – all relevant factors in ELT in Indonesia.” (my own personal statement)
Closing remarks: Last but not least, remarkable closing could give a very good impression for your application. Show your potential and why admitting you at the programme would be a right decision for the university.