Tutor profile: Hannah P.
When should you use が instead of は?
Although they are virtually interchangeable, は should be used when you are wanting to emphasize what comes after the は and が should be used when the emphasis of the sentence is on the subject or what comes before it.
What is the difference between "positive" and "negative" in "positive reinforcement, negative reinforcement" and "positive punishment, negative punishment" when talking about classical conditioning?
These two words often get confused when you move from regular spoken English to psychological terms because the meaning people often associate with the word "positive" is something always good while with "negative" people tend to think it's always something bad. However, in psychology the terms simply mean "an addition of something" for "positive" and "a subtraction of something" for "negative". Where this gets confusing is when it's attached to the words "reinforcement/punishment" because of the connotations attached to those words. The easiest way to remember is this: if you want to encourage an action to continue, use "reinforcement", if you want to encourage an action to stop, use "punishment". Now, when adding the "positive, negative" into the mix, "positive reinforcement" simply means "adding something to encourage an action to continue". This type of reinforcement is what most people think of when they train a dog for example. It is giving a treat for doing a desired behavior. If you think of the words "positive and negative" as meaning "plus and minus" it's a little easier to grasp.
Subject: English as a Second Language
How do you know when to use "the" instead of "a"?
In general, "the" is used when referring to a specific item. For example, when asking to use one particular pencil, you might say, "May I use the red pencil?" If there is no need to be specific, you can simply use "a".