Adjectives + that-clause or to-infinitive

ADJECTIVES + THAT-CLAUSE:

In this structure, an adjective is followed by a "that-clause," which acts as a noun complement, providing additional information about the subject or object of the sentence. Here's the general pattern:

Adjective + That-Clause

Example 1:

- I am certain that he will succeed.

Here, the adjective "certain" describes the speaker's level of confidence. The "that-clause" that follows ("he will succeed") provides more information about the content of the speaker's certainty.

Example 2:

- It is important that we respect the environment.

In this case, the adjective "important" emphasizes the significance of the action described in the "that-clause" ("we respect the environment").

ADJECTIVES + TO-INFINITIVE:

In this structure, an adjective is followed by the infinitive form of a verb (to + base form of the verb). This construction is used to express purpose, intention, necessity, or desire. Here's the general pattern:

Adjective + To-Infinitive

Example 1:

- She was kind enough to offer her assistance.

In this sentence, the adjective "kind enough" describes the level of kindness, and the "to-infinitive" phrase ("to offer her assistance") explains the action resulting from that kindness.

Example 2:

- It's hard to believe that he's gone.

Here, the adjective "hard" describes the level of difficulty, and the "to-infinitive" phrase ("to believe that he's gone") explains what is difficult.

Difference between the Structures:

While both structures involve adjectives and additional clauses, they serve different functions:

- Adjectives + That-Clause: This structure provides more information about the subject's opinion or perception regarding a situation or event.

- Adjectives + To-Infinitive: This structure emphasizes the level of an attribute and explains the subsequent action or state resulting from that attribute.