This is the 2444th most frequent Japanese word.
丁寧
Polite, courteous, or careful.
丁寧 is used to describe his speech style as polite and respectful.
彼の丁寧な話し方はとても好感が持てます。
His polite way of talking is very likable.
丁寧 is used to indicate doing the cleaning task with care and attention to details.
丁寧に掃除をすることが大切です。
It's important to clean carefully and thoroughly.
丁寧 indicates the manner of writing the letter as thoughtful and considerate.