Common English Mistakes #3: Singular v. Plural

Another post regarding English mistakes I hear around Korea - singular versus plural. This is another aspect of English that is seemingly tricky. I see how it can be tricky for Koreans since making things plural is not always necessary in Korean. Unfortunately in the English, this is not the case. Granted, I can figure out what my Korean friends are saying if they happen to mix up the singular/plural forms.

Example Dialogue:
A: Autumn is finally here! Let's go to the market and pick up some apples.
B: Sounds good, my friend taught me how to make apple cider. How about we try to make some this weekend?
A: Great! I've never made apple cider before.
B: It's delicious and not too hard to make.
A: How many apple do you we need?
B: You mean, "How many apples do we need?"...
A: Ah, right. Apples.

Example Dialogue:
A: I see you have a new Korean pop CD.
B: Right! It just came out today!
A: I see; it looks like the group has a lot of members.
B: That's right, there are 7 member in the group.
A: 7 members. Who is your favorite member?
B: I love them all! They are all handsome boy!
A: All of them are handsome boys...plural!
B: Ah...right...English is so hard ㅠㅠ

For most of my friends I'd say this mistake is rare but still comes up every now and then. Practice makes perfect as they say.

What mistakes do you hear often?
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Common English Mistakes #2: Articles

The most common mistakes with articles I hear are simply omitting them or using 'the' instead of 'a' and vice versa. I feel this is one of the hardest things to master for people learning English. While there are guidelines/rules regarding usage, most people I talk to still struggle. I tell them, it just takes time and practice (as with anything).

Example dialogue:
A: Wow, look at all the hats in this store!
B: Wow, there are so many!
A: How about this style? (Puts on hat) Do you like the red or the black one?
B: I like black one! It look good for you.
A: You mean, you like the black one. It looks good on me?
B: Ah, right. The black one.

A simple mistake, yes, but one that is obvious to any native speaker I would imagine. Another example of what I've heard:

Example dialogue:
A: How about we order a drink?
B: Yes, let's drink!
A: Let's see, they have many types of beer. Is beer ok?
B: Yes, the beer sounds good.
A: A beer sounds good? Great, I'll choose a few for us.

B Could have also responded with just "Beer sounds good". "The beer sounds good" isn't grammatically incorrect but it sounds weird since beer was the only option and no other beverage was mentioned as a choice. (English majors can correct me if I'm wrong).

What mistakes do you frequently hear?
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