Are the following sentences grammatically correct? I think #2 is correct, but I'm not sure.
- My room always be clean
- My room is always clean
Your #2 is correct. There are two rules in play here:
Because of these rules, #2 is correct and #1 is an error in standard English.
However, in a different syntactic frame the sequence "always be" could be correct. For example, if we add a modal verb then the sentence becomes:
Here, the modal verb would blocks verb agreement, and the adverb always follows the inflected verb, which puts it before the verb be.
The first might be grammatical in some dialects, but only the second is grammatical in Standard English (unless it forms part of a sentence beginning, for example, 'They insisted that . . .')