Pronoun

1. used to identify a specific person or thing close at hand or being indicated or experienced. "is this your bag?" used to introduce someone or something. "this is the captain speaking" referring to the nearer of two things close to the speaker (the other, if specified, being identified by ‘that’). "this is different from that"

2. referring to a specific thing just mentioned. "the company was transformed and Ward had played a vital role in bringing this about"

Determiner

1. used to identify a specific person or thing close at hand or being indicated or experienced. "don't listen to this guy" referring to the nearer of two things close to the speaker (the other, if specified, being identified by ‘that’). "this one or that one?"

2. referring to a specific thing just mentioned. "there was a court case resulting from this incident"

3. used with periods of time related to the present. "I thought you were busy all this week" referring to a period of time that has just passed. "I haven't left my bed these three days"

4. informal used in speech to draw attention to someone or something. "I turned round and there was this big mummy standing next to us!"

Adverb

to the degree or extent indicated. "they can't handle a job this big"