First rule of (language) teaching:
- Never ask your students if they understand!
First off, they will often be too embarrassed to say 'no', or too tired, or just not want to disrupt the lesson (as they see it). Secondly, they may think they understand, but in actual fact not understand at all. Thirdly, most of the time, what's really happening is that the teacher is subconsciously seeking approval from their students.
You need to use concept checking questions instead.
So, for example, you've just done an exercise where students have been reading a text with the verb blow. There's a matching exercise where your students have matched the word blow with a definition spend a lot of money on something.
Suppose you ask them: Do you understand?. They all say 'Yes'... What have you found out? Nothing! You have absolutely not one iota of evidence that they understood at all (which doesn't mean that they haven't understood - it just means that you don't know). Here's what you might do instead:
In order to find out if your students have really got the meaning of this verb we need to think about what problems or misunderstandings they might have. This is crucial, because it will inform you about what kind of checking you might need to do. So you'd want to think about the meaning, the form / usage and then the pronunciation to give you a guide, and then check them (in that order) using questions.
So, in terms of meaning, one problem students could have with that definition might be that blow doesn't just mean to spend a lot of money on something. It means to spend your money on something unimportant. If you blow your money you don't have anything substantial and important afterwards. To blow your money is to be frivolous. It's a negative thing. So you might want to use the following concept checking scenario:
- Last week I had ten thousand Euros in the bank. Yesterday I spent all of it on a Masters degree at Oxford University. Did I blow my money?
The answer of course should be no. But even if they say no, you don't have anything to check that against. So you'll need to ask "Why not?". You might want to contrast that with a different scenario. So a next question might be:
- Ok, so last week I had ten thousand Euros in the bank. I spent five thousand Euros at the casino, three thousand Euro's going to expensive nightclubs, and I spent two thousand Euros on a taxi from London to Edinburgh because I didn't want to get the train. Did I blow my money?
Of course, you will want to ask "Why?" after they give you the answer "Yes!".
An alternative way of checking their understanding is also very simple and less teacher-focused. You can simply say: "Tell me about the last time you blew some money on something". The phrase "Give me an example ..." is worth a billion "Do you understand?"s. You will understand very well from your student's answer whether they really understand or not. You may also find out whether they intuitively get the grammar or not and whether they have any pronunciation issues with the word.
Of course, you might also want to explicitly check whether they get the grammar. So you might want to board something like this
Yesterday (BLOW) / meal with my friends / $100.
And then say "Can you give me a sentence?". Of course what you are checking is whether they give you a sentence with $100 as the Direct Object and use the preposition on before the noun phrase "meal with my friends" (as opposed to in or with).
Lastly you might want to check if they understand exactly how the word should sound, and if they are able to physically pronounce the word correctly. I'll let you think about this one. Here are two questions/sentences you could use for checking this:
Which one do you think will work best?