Faculty (English)


Christina Celaya, US-English Pre-K and Kindergarten Teacher

Ms. Celaya is a native Phoenician and certified Early Childhood Educator with many years’ experience working in local and international schools. Her overseas experiences took her to the Philippines and Brazil. She holds a Reading Specialist certificate and has worked as an English Language Learner teacher, as well as, an Outdoor Environment teacher. Ms. Celaya grew up speaking Spanish and English in a bilingual environment and values the importance of learning about different cultures and languages.

Christina Celaya w195


Kari Nehlson, US-English Grades 2-4 Teacher

Ms. Nehlsen was born and raised in French-speaking West Africa. She has spent the last 5 years in New York City, obtaining her teaching degree and working toward her Masters degree in Special Education. She has been a camp counselor, youth mentor and most recently taught 4th grade in a small suburban town in New York.

Kari Nehlson w195


Marlena Sypel, US-English teacher, Lower School

Ms. Sypel graduated summa cum laude from the University of Notre Dame with a degree in English, a teaching certificate from Saint Mary’s College and a Master’s in Curriculum, Instruction and Assessment. Starting her career in Indiana, she moved to Arizona 2 years ago, working in the public system as an educator, academic coach and curriculum specialist. Marlena enjoyed a Study Abroad experience in London, where she developed a commitment to the global context of education by interning with a member of Parliament. Marlena is passionate and committed to her daughters’ bilingual education and considers ISA as ‘home.’ She is honored and humbled to join the team and support our learning community as a member of staff, as well as a parent.

Marlena Sypel w195


Melody Gardiner, US-English teacher, Lower School

Melody Gardiner is from Hawaii and has a Bachelor’s degree in Elementary Education from the University of Hawaii-Manoa and a Master’s degree in school counseling from the University of Redlands. She has taught Elementary Education in Hawaii, California, and Kuwait. In college, she studied abroad in Costa Rica as part of a Spanish immersion program where she volunteered in local schools. She has also spent time in Brazil teaching English as a second language. Mrs. Gardiner enjoys making learning fun and engaging. She says: “Children inspire me every day to be creative and live in the moment!”

Melody Gardiner w195


Keith Knight, Science and Math, Middle School Teacher

Mr. Knight is from Cary, North Carolina. He is a certified middle school math teacher and high school IB Diploma Program math teacher, and holds a Masters degree in Curriculum and Instruction: Mathematics K-14. He has taught mathematics for over 8 years. Mr. Knight is a veteran of the U.S. Air Force, and holds a nuclear engineering degree. For the past two years, he has been teaching High School and IB math in Taiwan.

Keith Knight w195


Vern Nicholas, After-School Activities Coordinator, 6th & 7th Grade US-English Teacher

Mr. Nicholas is from Portland, Oregon. He is a certified teacher and holds a Masters degree in Education as well as another Master’s in International Education Administration. He has over 10 years teaching in multiple subjects from K-12. Mr. Nicholas has teaching and overseas experience living and working in Vietnam, Mexico, Myanmar, the Philippines, and Spain. He is fluent in Spanish.

Verne Nicholas - English & Social Studies Teacher