Academic IELTS (Band 5 and Below) - Complexity

difficult to understand, deal with, or explain due to having many parts or factors

not easy to understand or analyze

not clear or easily understood

needing a lot of work or skill to do, understand, or deal with

confusing or difficult to understand, requiring extensive thought and analysis to make sense of the situation or problem at hand

not involving difficulty in doing or understanding

needing little skill or effort to do or understand

easy to comprehend or perform without any difficulties

clear and easy to understand

having or offering the simplest elements or level of understanding or functionality

not difficult to understand

noticeable and easily understood

easy to understand

easy to comprehend

clear in meaning or expression

clear enough to be easily understood