Invalid | Vocabulary

- [David] Hello, Wordsmiths. The word we're featuring in this video is invalid. That's right, it's not true. Or rather, that's what it means, invalid. Incorrect, false, not accepted. It's an adjective. It comes from Latin where the prefix in means not, and the word validus means strong. So it literally means not strong or weak. A weak argument, a weak law, someone's argument might be invalid because it was based on faulty evidence. When you look at invalid, can you recognize any other English words, anything with in or vow in it? Take 10 seconds of this music break to come up with some possibilities. Here we go. (upbeat music) Validate, right to prove that something's right or true. I validate your parking. I validate your feelings. Get you with the big validation stamp. Value, meaning something that has worth, right? Strength in worth. And inability, which is when you cannot do something. There's ability, right, when it can do a thing. And inability, which is its opposite. Let's spend some time talking about that in prefix, honestly, because it can get confusing. There are two different prefixes in English, both coming from Latin that are spelled and pronounced the same way. Both in, I-N, that have different meanings. In, or sometimes I'm, I-M, means not. Exactly like the native English, un. Like unlikeable, unlovely. Think invalid, impolite, infrequent, right. Not correct, not polite, not frequent. And then there's in, I-N, that means inside. This also sometimes appears as E-N, en, like insight looking inward or insert, which is to put something into something else. Or with the E-N, you can have it as enlist or enrich. But today in this video, we're talking about the in that means un. The in that means not. We'll return to this topic for sure in other videos. Now let's use invalid in a sentence. I can't log in. It says my password is invalid. Makes you furious. When something's invalid, it doesn't work. It isn't correct. When it's valid, it's proper and appropriate. But when it's invalid, it won't be accepted. It's no good. You know what is good though? You, you're good. I believe in you and the vocabulary journey that we are on together. You can learn anything, David, out.