‘Invest time in’ vs. ‘invest time into’ in English

by Jakub Marian

Tip: See my list of the Most Common Mistakes in English. It will teach you how to avoid mis­takes with com­mas, pre­pos­i­tions, ir­reg­u­lar verbs, and much more.

Long story short, the correct idiom is “invest time in something” (meaning “to put your time into something”):

correct He invested a lot of time in language learning.
wrong He invested a lot of time into language learning.

A few examples from the media:

People are willing to invest time in their career.
Social animals invest a lot of time in rearing their young.
Some firms were awarded multiple grants that enabled them to invest more time in developing their technology.

It is also worth noting that “invest time in” is a relatively new expression, as the following picture shows (it shows how often it was used in the given year in English literature).

invest time in

The use of the idiom only caught on in the 1960s, and it would have been considered unnatural before then. Nevertheless, it is completely acceptable (and commonly used) in modern English.

By the way, if you haven’t read my guide on how to avoid the most common mistakes in English, make sure to check it out; it deals with similar topics.