English and ESL Instructor
A pine tree is triangle. (Correct: A pine tree is triangular.)
An armed force is responsible for a country's defend. (Correct: An armed force is responsible for a country's defence.)
In English, an inflection means the addition of a suffix to change its syntactical function without changing its form. It is very important to select the correct inflection so that your sentence is grammatical.
For the purpose of this post, we will look at the word, intelligent. The word intelligent is an adjective, so we would use it to describe a noun:
Chris is an intelligent student.
If we add the suffix -ly to intelligent, we get intelligently, which is an adverb. Recall from the previous lesson about adjectives and adverbs that an adverb describes verbs, adjectives, or other adverbs:
Chris spoke intelligently.
The last inflection we can use for intelligent would be intelligence, where we drop the "t" and replace it with a "ce". Intelligence is a noun:
Chris has a high level of intelligence.
When deciding which inflection of a word to use, carefully consider what word class (noun, verb, adjective, adverb, etc.) you need exactly. It is really that simple!