一ひと筆ふで書かく

godan verb (-ku), intransitive verb

write a few lines; drop a line; write a note

Used when writing a short informal message or letter to someone. Often implies a brief, casual communication.

• 近きん況きょうを一ひと筆ふで書かいて送おくった。

  I dropped a line to let them know how I've been.

• お礼れいの一ひと筆ふでを書かくのを忘わすれていた。

  I forgot to write a short thank-you note.