What is the difference between "in this year" and "this year"?

Question

Travis , Tammy, and Shane, from Composition 115, spring semester, were sitting together on a leather bench in the sleekly lit lobby of my apartment building. The three of them had attended the same one-room schoolhouse, and they constituted the majority of their graduating class. Shane was holding a big carton that said "Xerox Paper" on the side. From deep within the box came a murmurous grunting and a sharp, rhythmic pulsing, as if it contained an internal organ. Everyone walking through the lobby looked at the box.

Tammy wore her hair in a high, stiffly sprayed froth of curls. She pushed back some strands and said, "Miss Diana, we just wanted to thank you for how much you've helped us with our thesis statements this year, and correct speech and whatnot, and Travis and Shane thought of this sweet little gift."

The sentences stated above have been chosen from the following link:

https://www.washingtonpost.com/archive/lifestyle/magazine/2004/07/11/the-goddess-of-flowers/f0ca69bf-fb03-47e2-bd6a-460073fbdf52/

If I write "you've helped us with our thesis statements in this year" instead of "you've helped us with our thesis statements this year", what differences in meaning will appear? That is, if I add an extra "in" before "this year", will it be wrong?

Answer 1

1. You've helped us with our thesis statements in this year.

2. You've helped us with our thesis statements this year.

Both sentences have the same meaning and are both fine grammatically, but by convention in is not usually used to refer to the current year, and will sound strange to native speakers. You should use sentence 2.

In is usually used for a year in the past or the future, followed by a date, such as:

The Battle of Hastings took place in the year 1066.

In the year 2050, we'll all have flying cars.