I need to write a letter.

Question

1. "I borrowed Mr. ABC from your division for the project..."

2. "He contributed a lot to the project."

How can I make the above sentences more formal?
1. What word can I replace "borrowed" with? How can I say the same thing in a more formal way?

2. "a lot" seems vague, what word should i use?

Thanks.

Answer 1

1. Mr. ABC from your division participated in our project.

2. He made substantial contributions to the project.