Premodifiers and Postmodifiers

 Pre-modifiers:

Pre-modifiers are the modifiers which modify the words that follow them in the sentence. Conventionally the adjectives are usually placed before the nouns. So, most of the adjectives are pre-modifiers. Adverbs are often placed before the words they modify.

Articles, determiners, demonstratives, proper adjectives, descriptive adjectives, compound adjectives, participles, etc. are the adjectives which come before the nouns and modify them.

Conjunctive adverbs, sentence adverbs, and some other adverbs can work being placed before the verbs/adjectives/other adverbs.

Post-modifiers

Post-modifiers are the modifiers which come after the words they modify. Customarily, the adverbs come after the verbs and modify them. However, some adjectives also come after the nouns and modify them.

Most of the adverbs of time, adverbs of manner, adverbs of place/direction usually come after the verbs they modify.

Appositives, prepositional phrases (adjectives/adverbs), infinitives (adverbs/adjectives), dependent clause, etc. usually come after the nouns they modify.