Which characteristic defines an inflected language?

The defining characteristic of an inflected language is that words can change their form based on grammatical rules. Inflection refers to the modification of a word's form to express different grammatical features such as tense, mood, voice, aspect, person, number, gender, and case. For example, in languages like Latin or Russian, verbs may change their endings to reflect the subject's number or tense, and nouns may change according to their case. This inflection adds a layer of meaning to the words beyond their base forms.

The other options touch on language characteristics but do not specifically address the concept of inflection. For instance, some languages may rely more on context and possess fewer word forms, but this does not capture the essence of inflected language, which involves systematic changes based on grammatical rules. Similarly, indicating that words do not change based on their usage contradicts the definition of an inflected language, as it fundamentally relies on those changes. Lastly, while some may find inflected languages more challenging to learn due to their complexity, this characteristic does not define what makes a language inflected, but rather speaks to learner experience.