Use it Right While Speaking or Writing English

Affect and Effect-
  • Affect is a verb meaning to have influence on something; to act upon emotions; to move something; to touch something; to attack or to infect.
  • Effect is most usually a noun and it means the result of some action or the power to produce a result.
Examples:
The petrol prices affected the sales adversely.
A high fever can affect the brain.

Exposure to the sunlight had the effect of on your eyes.
The effect was astonishing.

Assure, Ensure, and Insure-
 The verbs assure, ensure, and insure all mean "to make certain or secure." Here are the definitions along with some examples to help clarify the distinctions.

  • Assure: to promise or say with confidence. Assure is something you do to a person to remove doubt or anxiety
  • Ensure: to make sure something will/won’t happen. Ensure is something you do to guarantee an event or condition
  •  Insure: to issue an insurance policy. Insure can be done to a person, place, or thing
Examples:
Let me assure you that I will be at the meeting at noon.
He assured me that the product would be delivered tomorrow.

 To ensure my family’s safety, I have installed an alarm system.
 A firewall helps to ensure that hackers don't attack your PC.

 I will insure my home with additional fire and flood policies.
 In most countries you need to insure your car against accidents.

Revert And Return-
 The most common meaning of revert is “to return to an earlier condition, time, or subject.” It is to go back to the previous state.
Synonyms are: regress; turn back; return
Today, most people in India have begun to use it mistakenly instead of “reply,” writing when they want you to get back to them about something, “revert to me at this address.” This would literally mean they are asking you to become them.
Avoid saying “revert back.”
Saying “revert back” is like saying “return back” or “go back back.” The “back” is redundant here.
Return is to come back, or begin again, to appear again; to revert; to pass back into possession.
Examples:
I reverted to gmail after trying out the new email service.
Note: “return back” is incorrect in above. 
Some control changes keep reverting back to default after restarting the game, no matter how many times the configuration was saved.

I will return your book soon. (NOT “return back your book”).
We will return to Shimla on Sunday (NOT “return back to Shimla”).
  
Untill, Up To, and Uptill
  •   Until specifies a certain point in time; use of until is essentially related to time limit
  •   Up to specifies a certain limit of something; use of up to is not essentially related to a time limit
  •   Uptill is contraction for “up untill”. Uptill means the same as “untill”; however, it is best avoided
     in formal writing or speaking.

Untill and uptill (if you insist on using) are always written as one word and with a single “l”.
Up to, however, must be written as two separate words.
Until and till are interchangeable; the only difference is that when used as the first word in a sentence, until is used.
Examples:
You can carry up to (not until) 20 kg of luggage.
He could have run up to (not until) 15 km in ideal weather.

You have until (not up to) 3 p.m. to finish the work.
He will not join until the end of the week.
Until you agree to talk, things cannot improve.