The most common synonyms for the everyday words amazing, awful, interesting and unhappy are, respectively, incredible, dreadful, fascinating and miserable. Mad is another frequently used word; though having more than one meaning, its most common synonyms tend to be angry, furious and enraged. Old is a word with positive synonyms, such as mature and experienced, and others often perceived as negative, such as worn and used. Those who think a lot can also be said to conceive, ponder and reflect.
One's job may sound more appealing if its synonym "vocation" is the word of choice. Similarly, the dog likes the cat, but can also enjoy, relish and appreciate the cat. Terrific is a word that can be ramped up to extraordinary, magnificent and marvelous when a synonym is needed. Synonyms for the word frequent include recurrent, continual and incessant, which are similar to the synonyms for regular: standard, routine and customary.
The synonyms for the word see, such as behold and gaze, lean toward the romantic, while some of its synonyms, such as witness, notice and regard, are more appropriate for the attorney or business person. For those hoping to elevate the register of their speech, replacing the word "next" with "thereafter" or "successively" (or truly, genuinely and inarguably) fits the bill.