1. I'll look over your application and call you in a few days.

2. I'll look thoroughly your application and call you in a few days.
(Is 'look thoroughly' the opposite of 'look over'?)

3. I will look closely at your application.

4. I will take a close look at your application.

(Do #2, #3, and #4 have the same meaning? Do you have some other expressions which are similar to #3 or #4?

Sentence 2 is incorrect.

Sentences 3 and 4 mean the same as what you're trying to say in sentence 2, so I'd use 3 and 4, or substitute "thoroughly" in place of "closely" in sentence 3.

You could also say, "I'll take a good look at your application."

1. The phrase "look over" in this context means to review or examine the application briefly. It implies a quick or cursory glance at the document. The intention is to gather a general understanding or overview of the application before making a decision. The decision to call or not call the person will be based on this initial review.

2. The phrase "look thoroughly" can be considered as a more intensive or detailed version of "look over." It suggests a deeper examination or analysis of the application. It indicates a careful and meticulous review of the document, potentially noting specific details, strengths, and weaknesses. However, it is not necessarily the opposite of "look over." Instead, it can be seen as a more comprehensive approach to reviewing the application.

Regarding the expressions in question:

3. "I will look closely at your application." This phrase conveys the idea of examining the application attentively and paying close attention to the details. It suggests a more thorough evaluation than simply "looking over" it.

4. "I will take a close look at your application." This expression has a similar meaning to the previous one. It implies a deeper examination of the application, focusing on observing and analyzing the details with care. "Taking a close look" signifies a deliberate and intentional inspection.

In terms of similarity, #3 and #4 have nearly identical meanings. They both emphasize a careful examination of the application, suggesting a thorough review. However, #4 slightly reinforces the intention by using the word "take," indicating an active approach in examining the document.

Some other similar expressions to #3 and #4 would include:

- "I will give your application a thorough review."
- "I will carefully evaluate your application."
- "I will closely scrutinize your application."
- "I will meticulously examine your application."

These expressions convey the same idea of carefully and attentively reviewing the application to gather a detailed understanding before making a decision.