I WOULD do anything for love, but I WON'T do that

[English Maiden]

Hi, Joe!
The subject of this post is that last verse from a popular rock-ballad song by a popular American rock band in the '90s. That line, however, has got me wondering why the modal verbs in it are not the same. Why is it "would" in the first half (I would do anything for love) and "will" ([But] I won't do that) in the second half of that compound sentence? What really is the difference between saying "you would/would not do something" and saying "you will/will not do something"? Please shed some light on this matter for me. Thanks loads in advance!

[English Maiden]

Also, can "that's" be a contraction for "that was"? I often hear native and non-natife speakers say statements like "That's what I was told," "That's what I thought," and "That's not what I did/said." Clearly in the above sentences I presented that "that's" means "that was" since all the actions or situations being described are in the past, am I correct? If yes, does this mean that "that's" can also stand for "that was"?

[Joe Carillo]

Hi, Joe!
The subject of this post is that last verse from a popular rock-ballad song by a popular American rock band in the '90s. That line, however, has got me wondering why the modal verbs in it are not the same. Why is it "would" in the first half (I would do anything for love) and "will" ([But] I won't do that) in the second half of that compound sentence? What really is the difference between saying "you would/would not do something" and saying "you will/will not do something"? Please shed some light on this matter for me. Thanks loads in advance!

As taught to us early in English grammar, the auxiliary verb “will” expresses these two major senses: (1) the simple futurity of a particular action, as in “She will get married tomorrow morning,” and (2) one’s determination, insistence, persistence, or willfulness at present to do something, as in “I will follow you no matter where you go.” In both senses, “will” inflects to the past-tense “would” in complex sentence constructions like “She said (that) she would get married tomorrow morning” and “He said (that) he would follow me no matter where I go.”

What complicates matters, however, is that the auxiliary “would” doesn’t only serve as the past tense of “will” but also works with verbs to evoke several other senses. I’ll cite only a few of those senses that are directly related to your question, namely: (3) to express an intent, wish, or desire, in “Those who would testify against us will be expelled”; (4) to express choice or consent, as in “The court would terminate the proceedings if it could”; (5) to express possibility or contingency, as in “If she had gone to medical school, she would be a surgeon by now”; and (6) to express custom or habitual action, as in “We would go to our farmhouse during weekends.”

Now let’s take a close look at that line from the song lyrics you cited: “I would do anything for love, but I won’t do that.” Here, the first clause “I would do anything for love” expresses the sense of the speaker’s intent to do something. This, of course, is what’s contemplated in Sense 3 as described above, with “would” serving as an auxiliary to the main verb “do” to express an intent, wish, or desire. It’s a timeless declaration of the speaker’s strong determination to do something.

But why, you ask, does the second clause of that compound sentence, “I won’t do that,” use the verb “will” instead? Of course, that sentence actually doesn’t use “will” in the negative sense but “won’t,” the American English colloquial contraction for “will not.” Whether in the form of “will not” or “won’t,” however, the auxiliary “will” works with the verb “do” here according to Sense 2 as described above, which is to evoke not simple futurity but the speaker’s strong determination, insistence, persistence, or willfulness at present—now—to do something. It would therefore be incorrect here to use the past-tense “would not” or “wouldn’t.”

As to your last question: What’s the difference between saying “You would do something” and saying “You will do something”? The difference is in the degree of modality or strength of the speaker’s expectation or affirmation of the give action. Remember that “will” and “would” are modals, with “will” expressing a speaker’s comparatively stronger expectation or affirmation than “would.” So, when someone tells you “You will do something for me,” he or she is practically certain that you’ll do what’s being asked; you are just short of being ordered or commanded to do it. In contrast, when someone tells you “You would do something for me,” the speaker’s expectation isn’t as strong and just amounts to a request.

[Joe Carillo]

Also, can "that's" be a contraction for "that was"? I often hear native and non-natife speakers say statements like "That's what I was told," "That's what I thought," and "That's not what I did/said." Clearly in the above sentences I presented that "that's" means "that was" since all the actions or situations being described are in the past, am I correct? If yes, does this mean that "that's" can also stand for "that was"?

In formal writing, “that’s” is unacceptable as a contraction for “that was.” It would betray the writer’s carelessness or downright ignorance of English grammar, particularly in the usage of the tenses. For instance, would you allow yourself to be caught writing this in a school essay: “That is what I was told by my teacher yesterday” or “That’s what I was told by my teacher yesterday”? Of course not! You’d feel safer and grammatically righteous writing “That was what I was told by my teacher yesterday?” So my answer to your question, as far as formal writing is concerned, is a firm no: “that’s” can’t stand for “that was.”

In informal conversations, however, people would always be predisposed to make “that’s” stand for “that was,” for economy in words is precisely why contractions are made in the first place. They normally wouldn’t take the trouble saying “That was what I was told by my teacher yesterday?” (Notice that the construction “was what I was” sounds like a tongue-twister that a speaker would naturally want to avoid.) Instead, without even consciously thinking of the violation in tense involved, they would usually contract “that was” to “that’s” and say “That’s what I was told by my teacher yesterday.” Anyone will surely take offense if you pointed out the tense violation, so if you are the listener, I think you’d strongly hesitate pointing out such a petty grammar wrinkle in the first place.

So when it comes to using “that’s” as a contraction for “that was,” just keep in mind that you can get away with only in informal spoken English but never in formal English writing.

[English Maiden]

Thanks a lot for your reply, sir. I notice that you often use the modal "would" in your explanations, although I don't quite understand why. Anyway, about using "that is/that was," I also find it confusing to choose which one to use with the word "meant." For example, if I want to say to someone that they misunderstood my statement, should I say "That IS not what I meant" or "That WAS not what I meant"? Another example, when I want to clarify what I just said to avoid confusion or misinterpretation, should I say "This IS what I meant by..." or "This WAS what I meant by..."? "What I meant by what I said IS..." or "What I meant by what I said WAS..."? Please clarify things for me. Thanks in advance!

[Joe Carillo]

As I said in my reply to your original question, “would” is used in two classes of senses in English. The first is as the simple past tense of “will,” as in “Helen said she would go home before midnight last night, and she did” (here, the speaker is reporting having heard Helen say, in these exact words: “I will go home before midnight”); and the second as the modal* “would” to express a strong wish or desire, as in “I would love to be in Paris in springtime!” If you check with a good dictionary like, say, Merriam-Webster’s 11th Collegiate Dictionary, you’d find that the modal “would” could evoke several other senses than just wishes and desires; it could also evoke preference, habit, intent, consent, choice, contingency, possibility, or probability—and I must say that they constitute a big mouthful compared to the single-bite sense of the simple past-tense “would”!

About the choice between using “that is” and “that was” in sentences like "That (is, was) not what I meant,” use the present-tense “that is” or “this is” if the statement referred to is, say, in a whiteboard or blackboard in front of you or in an e-mail message you are replying at the moment: “(That, This) is not what I meant.” On the other hand, use the past tense “that was” when verbally contradicting a report about a statement you made in the past that’s now being quoted to you wrongly by someone; in this case, you reply would be “That was not what I meant.”

When you want to clarify what you have just been said, use the present tense all the time for your clarification: “This is what I meant.” “What I meant is this.” Because of the immediacy of your response, you can even use the present tense “mean” instead of the past particle “meant” in such responses: “This is what I mean.” “What I mean is this.” “What I mean in what I’ve just said is this…” Under such circumstances, no one could accuse you of wrong grammar when you use the present tense all throughout your clarification.
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*Be definition, a modal is an auxiliary verb that relates to or constitutes a grammatical form or category indicating predication of an action or state in some manner other than as a simple fact. Examples are “can,” “could,” “would,” “must,” “may,” “might,” and “ought.”