To find something is to locate or obtain it. To encounter something is to come upon it unexpectedly. Those who find something are usually looking for it, and may be delighted or relieved to find it. Those who encounter something—not so much! Confrontation and conflict accompany encounter in many contexts because the word entered English poised for battle; its earliest sense was “to meet in conflict,” as in “We will encounter the enemy at dawn.” Today, encounter is used less to talk about daybreak adversaries, and more about unforeseen obstacles and difficulties.
The adjective kind implies a deep-seated benevolence and sympathetic nature. Amiable emphasizes congeniality. Someone who is amiable is friendly, agreeable, and pleasant to be around. Amiable also connotes affability, or an easy manner that invites approach and conversation (someone who is affable is easy to talk to). Amiable is close in spelling and meaning to another well-intended adjective, amicable. But context is key: amicable usually describes friendliness or goodwill where there could otherwise be hostility.
To say something is to express it verbally. To assert something is to state it with assurance, confidence, or force. Compared to say, which often indicates simply the act of speech, assert describes an insistent and sometimes even aggressive manner of expressing oneself; one who asserts something aims to persuade others to agree with or accept their position.