What is the comparative form of “sincerest”?

The comparative form of “sincerest” is “more sincere”.

Example

Her apology seemed more sincere than his.

Example

I find her compliments to be more sincere than his.

What is the superlative form of “sincerest”?

The superlative form of “sincerest” is “most sincere”.

Example

Among all the candidates, she seemed the most sincere.

Example

His words of encouragement were the most sincere I've ever heard.

Why is this expression not used with most, more?

"Most" and "more" are used with "sincere" to form the comparatives and superlatives. The forms "more sincere" and "most sincere" are commonly used to indicate a higher degree of genuineness or heartfelt expression.

Does this expression have an irregular comparative/superlative form?

"Sincere" follows the regular pattern of using "more" and "most" for forming comparatives and superlatives.

Expressions with similar meanings to “more sincere”

more genuine

Used to describe something that is more authentic or true.

Example

His smile seemed more genuine than hers.

more heartfelt

Used to indicate that something is more deeply felt or expressed.

Example

Her thank-you note was more heartfelt than his.

Expressions with similar meanings to “most sincere”

most genuine

Used to describe something that is the most authentic or true.

Example

Her apology was the most genuine expression of remorse.

most heartfelt

Used to indicate that something is the most deeply felt or expressed.

Example

His speech at the graduation ceremony was the most heartfelt moment of the event.

Using than with comparative “more sincere”

When using the comparative form "more sincere" to compare two things, you would use "than" to connect the two parts of the comparison: Example: "Her apology seemed more sincere than his." Here, "than" is used to show that the level of sincerity in her apology is higher than the level of sincerity in his.

How can I use this expression in context?

“more sincere” and “most sincere” can be used in a variety of situations to compare speed.

1Apologies
Her apology was more sincere than his.
Her apology was more sincere than his.
2Compliments
I find her compliments to be more sincere than his.
I find her compliments to be more sincere than his.
3Expressions of gratitude
Her thank-you note was more heartfelt than his.
Her thank-you note was more heartfelt than his.
4Words of encouragement
His words of encouragement were the most sincere I've ever heard.
His words of encouragement were the most sincere I've ever heard.