Explanation:

- A person very reserved in speech refers to someone who is not very talkative and often keeps their thoughts to themselves.

- Confident: This describes someone who is self-assured and bold in their speech and actions. It doesn't fit a reserved person.

- Reticent: This means someone is introverted or not inclined to speak freely. It perfectly describes a reserved speaker.

- Eloquent: This refers to someone who speaks fluently and persuasively. It implies they are effective communicators, not reserved.

- Adamant: This describes someone who is unyielding in their opinion. It relates more to determination rather than speech habits.