The English language is a relatively _____________________ language, making it more flexible to use, but harder to learn.

The English language is described as uninflected, which indicates that it relies less on changes in word form to convey grammatical relationships compared to other languages that are highly inflected. In uninflected languages, the structure often remains more fixed, and meaning is typically derived from word order and auxiliary verbs rather than extensive word endings or changes. This characteristic contributes to the flexibility of English in usage, as it allows for variations in expression without needing to adhere to strict inflectional rules.

Moreover, the uninflected nature makes English somewhat challenging for learners. This is because, even though the syntax might appear straightforward, the number of exceptions, idiomatic expressions, and nuances can complicate the learning process. This complexity arises from the need to master a range of vocabulary and the subtleties of word placement in sentences to produce grammatically correct and meaningful expressions. Thus, the adjective "uninflected" accurately captures the balance of flexibility and difficulty associated with learning the English language.