Both ‘Partly’ and ‘Partially’ mean ‘not completely’.
- The project was partly finished.
- The project was partially finished.
‘Partly’ is used to talk about the reason of something and it is often followed by ‘because of’ or ‘due to’.
1. The journey was tiring partly because of bad weather.
2. The game was boring partly due to absence of star players.
3. His speech was not interesting partly because of poor preparation.
4. Her English is bad partly due to lack of confidence and regular practice.
5. Jack became angry partly because of his failure to express himself in front of others.
‘Partially’ is used to talk about physical conditions or situations of something.
1. The road was partially finished.
2. She is partially blind.
3. The speech was partially prepared.
4. The students were partially taught.
5. The water project was partially completed.
Note: ‘Partially’ is followed by past participle – the verb forms like completed, finished, taught, prepared, etc.