"Wearing his hat and coat, he looked outside and decided he should take an umbrella as well."
2.AdverbTo the same effect.
"They might as well walk as drive in this traffic."
3.AdverbMe too.
4.AdverbAn intensifier. Actually; really.
"―Would you though? ―I would as well.; ―She looks so much like her mum, don't you think? ―Oh my god, she does as well!; ―Good morning Mr Brown! ―Good morning! I see you've got little Molly [pet dog] out for a stroll as well!"