Are “first / last” adjectives, adverbs ?
1) I came in first this semester.
2) I came first on the first day of class.
3) The first thing I do when I come home is…
How should I know which parts of speech first/last belong to?
Thank you for your help.
Look at where the word sits in the structure. For example,
2) I came first on the first day of class. (determiner + adjective + noun)