I hope someone can help me figure it out. I get so confused while trying to explain or understand the use of the phrases above. I've seen this "I'm tired of always being the one to text first" but as to what I know, it must be " I'm tired of always being the one who texts first". Which one is correct? Or are they both correct? Thanks in advance.
They're both widely used and accepted to be correct. I can't think of a case where they're not interchangeable. Can you?
Except: References to past incidents will mostly use 'the one who'. For example: "Oh! Is she the one who called the police at your last party?"
I'm tired of always being the one who texts first.
I'm tired of always being the one to text first.
These are both grammatical, and in this context mean the same thing. The first uses a regular relative clause with a tensed verb. The second uses a non-finite relative clause. This relative clause has to be non-finite because the Subject of the clause is missing. Notice that because of this it has no past or present tense. We infer the time period referred to from the verb in the matrix clause (the main clause) and from the context.