Partially vs. Partly
Dictionaries treat the adverbs as close synonyms. A useful distinction is contextual: “partly” often fits causal phrases such as “partly because,” while “partially” can sound more literal or formal when describing incomplete extent.
Both usually mean “not completely” or “to some degree.” “Partly” is also very natural when introducing one contributing reason or factor, so the choice is often about phrasing and emphasis rather than a hard rule.
Key details
Choose the right form
| Meaning / context | Use | Decision |
|---|---|---|
| incomplete extent or degree | partially / partly | Either can work; choose the wording that reads naturally in context. |
| one contributing reason or factor | partly | Often the more idiomatic choice, especially before “because” or a reason phrase. |
| formal description of incomplete coverage or completion | partially | Common when the focus is literal extent, though “partly” may still be possible. |
Quick tests
Decision test
Are you introducing one reason among several rather than simply describing incomplete extent?
If yes: “Partly” is often the more natural choice.
If no: For incomplete extent, both may work; “partially” can be more formal or literal.
Caveat: Do not invent a strict semantic division: these words overlap substantially and are often interchangeable.
Examples
The road was partially blocked.
The adverb describes incomplete extent.
The delay happened partly because of the weather.
“Partly” naturally introduces one contributing cause.
The view was partly obscured by trees.
“Partly” can also describe incomplete extent, showing the overlap.
Further guidance
Core difference
Either can work; choose the wording that reads naturally in context.
Fast Test
“Partly” is often the more natural choice. For incomplete extent, both may work; “partially” can be more formal or literal.
Usage Boundary
Do not invent a strict semantic division: these words overlap substantially and are often interchangeable.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- partially (opens in a new tab)Cambridge University Press · Partially means not completely and is listed with partly as a synonym.
- partly (opens in a new tab)Cambridge University Press · Partly means to some degree but not completely, and its examples also show use when identifying one contributing reason or factor.