hard on (someone's) heels

Translations
по пятам
The detective was hard on the thief's heels throughout the chase.
Детектив гнался за вором по пятам во время всей погони.
Definitions
Arriving or following very closely behind someone; in close pursuit of someone, either literally (such as walking or running right behind them) or figuratively (such as succeeding or competing closely with them).
Words
hard

adverb
неотступно
on

preposition
за
someone

pronoun
кем-то
s
притяжательная форма
heels

noun
пятами