Partially vs. Partly — What's the Difference?

Partially is often used to describe the degree to which an action, process, or state is incomplete. It implies that something has been done, but not wholly, focusing on the extent or degree of completion. For example, a task can be partially completed, indicating that progress has been made, but it is not yet finished. On the other hand, partly refers to one of several parts or aspects of something, emphasizing the specific section or component involved rather than the degree of completion. When something is described as partly responsible, it indicates that it is one of a few contributing factors, not necessarily reflecting on how much or to what extent.

The use of partially is common in contexts where the emphasis is on the incomplete nature of an action or state, suggesting that more remains to be done. It conveys a sense of something being not entirely realized or fulfilled. Whereas partly is used when the focus is on distinguishing among different components or aspects that make up a whole, suggesting that only one part or some parts are involved or affected, without necessarily commenting on the extent of involvement.

Partially can also imply a qualitative assessment, suggesting that something does not fully meet a certain standard or condition. This usage is prevalent in evaluations or critiques, where something might be partially effective, indicating it does not fully achieve its intended effect. Partly, however, leans towards a quantitative distinction, separating a whole into distinguishable segments, where the emphasis is on the identity of the segments rather than the quality of completion or effectiveness.

In legal or formal documents, partially is often preferred to denote the extent of applicability, validity, or responsibility, emphasizing the degree to which something is applicable or true. Conversely, partly might be used to specify the particular aspects or sections of a document or law that are relevant, focusing on dividing the subject into relevant portions.

When discussing involvement or contribution, partially tends to imply a limited degree of involvement or contribution to a whole, suggesting that while there is some involvement, it is not complete or total. Partly, in contrast, is used to highlight the fact that only certain parts, aspects, or individuals are involved, without making a judgment about the degree of that involvement or contribution.