[sql-server] Check if starting characters of a string are alphabetical in T-SQL

Is it possible, just using TSQL, to check if the first two characters of a varchar field are alphabetical?

I need to select from my_table only the rows having my_field beginning with two alphabetical chars. How can I achieve this?

Is it possible to use a regex?

select * from my_table where my_field Like '[a-z][a-z]%'