What's the difference between especially and specially?
Here are some general rules which might help you choose which to use.
With an adjective, they can both mean 'more than normal' but especially is much more common. In informal English, you can use that. For example:
This vocabulary isn't especially/specially/that difficult.
Use especially to mean 'particularly' (or 'more than other things'). It is usually used after a comma.
I love watching films, especially thrillers.
Use specially to mean 'for this particular purpose'. It is often used with a passive verb structure.
These houses were specially built for small families.
It's Halloween, so I rented this horror film specially (for this occasion).
We don't usually use especially or specially at the start of a sentence. Instead, use in particular to link two sentences.
I love watching films. In particular, I really like horror films.
Choose the best word/expression to complete these sentences.
Note: This area of English is (especially!) complicated, and some websites with advice on this seem to disagree with each other. It can be a good idea to use corpus data (e.g. from the British National Corpus) which gives you real examples of how people use vocabulary.