Finally, at last, lastly and in the endall have a meaning of ‘after a period of time’. However, we use them in different ways.
Finally
We usefinallyto refer to something that happened after a long time and usually after some difficulties. In this meaning,finallymost commonly occurs in the normal mid position for adverbs, between the subject and the main verb, after the modal verb or the first auxiliary verb, or afterbeas a main verb:
There were no taxis andwefinallygothome at 2 pm.
She’s had over twenty interviews but Jasminehasfinallygota job as a journalist.
At last
We useat lastwhen we have been impatient as a result of long delays. Likefinally, at lastoccurs in the normal mid position for adverbs as well as in front and end position:
At lastI’ve discovered how to print envelopes on my printer!
She hasat lastgiven me the book she promised me.
They’re hereat last!!We’ve been waiting half an hour.
Lastly
We uselastlyto refer to something that comes at the end of a long list:
We need eggs, milk, sugar, bread and,lastly, we mustn’t forget yoghurt for Dad.
I’ve thanked my parents butlastlyI must thank all my friends for their help.
In the end
We usein the endto refer to a conclusion after a long process, after a lot of changes or after a lot of discussion:
We were going to ski in Austria, then the South of France andin the endwe decided to go to Italy.
And then,in the end, after months of discussion they offered to buy our house.