'Stuff' is the word for uncountables, where 'thing' is the word for countables:
'There is a lot of stuff in my pocket.'
'There are a lot of things in my pocket.'
'Stuff' can be countable in some special uses (like fabrics), but it is not a use that you will meet often.
You should not use 'alike' as you did. 'Alike' as an adjective or adverb needs two referents (implied or overt):
'You and I are alike in enjoying English.'
'I eschew asparagus and rutabagas alike.'
- For Teachers