Correct spelling, explanation: the word especially comes from the Middle English word especial, which is derived from the Old French word especial (special). Over time, especial evolved into especially, and it has been used in English since the 15th century. While specially and especially both have connections to the idea of something being unique or distinct, they have evolved to serve slightly different linguistic functions. Especially is used to single out a particular thing for emphasis within a category.

Definition of especially:
adverb, very much; more than usual or more than other people or things
She loved all types of animals, but she was especially fond of cats.
The children were excited about the zoo trip, especially because they wanted to see the lions and tigers.

Collocations with especially:
Some most commonly used collocations include:
1. Especially important/significant: this collocation is used to emphasize the higher level of importance or significance of a particular thing or idea within a context.
In a team project, communication is especially important to ensure everyone is on the same page.
2. Especially good/great: when something is described as especially good or especially great, it means that it stands out or excels in comparison to others.
The seafood at that restaurant is always especially good.
3. Especially true/valid/applicable: this collocation is used to highlight the accuracy, validity, or relevance of a statement or concept, particularly in specific situations.
In times of economic uncertainty, the advice to save money is especially applicable.
4. Especially relevant/important: when something is especially relevant or especially important, it means that it has a higher degree of relevance or significance within a given context.
In the context of environmental issues, recycling is especially relevant.

Correct spelling, explanation: the words specially and especially have similar meanings, but their etymologies and usage histories are distinct. The word specially is an adverb that is derived from the adjective special. It comes from the Middle English word special, which is derived from the Old French word especial (special). Both special and specially ultimately trace their origins to the Latin word specialis, which means particular or individual. In modern usage, specially is used to indicate that something is done or designed in a particular manner or for a specific purpose.