What is a good idiom for telling someone something that they already know a lot about?

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Like when you're in a conversation with someone about something and you're telling them about XYZ, but it turns out they are already experts in the subject matter, an idiom like trying to teach the teacher.

idiom-requests

share|improve this question

edited 16 mins ago

Peter Mortensen

2,39362436

asked 12 hours ago

user186103

291

• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  Teach fish how to swim. But, if somebody tells you that your and you are are not the same, don't respond with this idiom!
  – mahmud koya
  11 hours ago
  
  

  
  
  
  


• 
  
  
  

  
  7
  

  
  
  
  
  
  

  
  Possible duplicate of "Teaching fish to swim"
  – Mari-Lou A
  10 hours ago
  

  
  
  
  


• 
  
  
  

  
  4
  

  
  
  
  
  
  

  
  and also Idiom for explaining something to someone who clearly knows the topic (probably better than you)
  – Mari-Lou A
  10 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  and also english.stackexchange.com/questions/465018/…
  – michael.hor257k
  8 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  I must say, "Teach fish how to swim" is not very current / not popular at all. in both US / BR
  – Fattie
  5 hours ago
  

  
  
  
  

 | 
show 4 more comments

up vote
4
down vote

favorite

Like when you're in a conversation with someone about something and you're telling them about XYZ, but it turns out they are already experts in the subject matter, an idiom like trying to teach the teacher.

idiom-requests

share|improve this question

edited 16 mins ago

Peter Mortensen

2,39362436

asked 12 hours ago

user186103

291

• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  Teach fish how to swim. But, if somebody tells you that your and you are are not the same, don't respond with this idiom!
  – mahmud koya
  11 hours ago
  
  

  
  
  
  


• 
  
  
  

  
  7
  

  
  
  
  
  
  

  
  Possible duplicate of "Teaching fish to swim"
  – Mari-Lou A
  10 hours ago
  

  
  
  
  


• 
  
  
  

  
  4
  

  
  
  
  
  
  

  
  and also Idiom for explaining something to someone who clearly knows the topic (probably better than you)
  – Mari-Lou A
  10 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  and also english.stackexchange.com/questions/465018/…
  – michael.hor257k
  8 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  I must say, "Teach fish how to swim" is not very current / not popular at all. in both US / BR
  – Fattie
  5 hours ago
  

  
  
  
  

 | 
show 4 more comments

up vote
4
down vote

favorite

up vote
4
down vote

favorite

Like when you're in a conversation with someone about something and you're telling them about XYZ, but it turns out they are already experts in the subject matter, an idiom like trying to teach the teacher.

idiom-requests

share|improve this question

edited 16 mins ago

Peter Mortensen

2,39362436

asked 12 hours ago

user186103

291

Like when you're in a conversation with someone about something and you're telling them about XYZ, but it turns out they are already experts in the subject matter, an idiom like trying to teach the teacher.

idiom-requests

idiom-requests

share|improve this question

edited 16 mins ago

Peter Mortensen

2,39362436

asked 12 hours ago

user186103

291

share|improve this question

edited 16 mins ago

Peter Mortensen

2,39362436

asked 12 hours ago

user186103

291

share|improve this question

share|improve this question

edited 16 mins ago

Peter Mortensen

2,39362436

edited 16 mins ago

Peter Mortensen

2,39362436

edited 16 mins ago

Peter Mortensen

2,39362436

2,39362436

asked 12 hours ago

user186103

291

asked 12 hours ago

user186103

291

asked 12 hours ago

user186103

291

291

• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  Teach fish how to swim. But, if somebody tells you that your and you are are not the same, don't respond with this idiom!
  – mahmud koya
  11 hours ago
  
  

  
  
  
  


• 
  
  
  

  
  7
  

  
  
  
  
  
  

  
  Possible duplicate of "Teaching fish to swim"
  – Mari-Lou A
  10 hours ago
  

  
  
  
  


• 
  
  
  

  
  4
  

  
  
  
  
  
  

  
  and also Idiom for explaining something to someone who clearly knows the topic (probably better than you)
  – Mari-Lou A
  10 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  and also english.stackexchange.com/questions/465018/…
  – michael.hor257k
  8 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  I must say, "Teach fish how to swim" is not very current / not popular at all. in both US / BR
  – Fattie
  5 hours ago
  

  
  
  
  

 | 
show 4 more comments

• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  Teach fish how to swim. But, if somebody tells you that your and you are are not the same, don't respond with this idiom!
  – mahmud koya
  11 hours ago
  
  

  
  
  
  


• 
  
  
  

  
  7
  

  
  
  
  
  
  

  
  Possible duplicate of "Teaching fish to swim"
  – Mari-Lou A
  10 hours ago
  

  
  
  
  


• 
  
  
  

  
  4
  

  
  
  
  
  
  

  
  and also Idiom for explaining something to someone who clearly knows the topic (probably better than you)
  – Mari-Lou A
  10 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  and also english.stackexchange.com/questions/465018/…
  – michael.hor257k
  8 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  I must say, "Teach fish how to swim" is not very current / not popular at all. in both US / BR
  – Fattie
  5 hours ago
  

  
  
  
  

5

5

Teach fish how to swim. But, if somebody tells you that your and you are are not the same, don't respond with this idiom!
– mahmud koya
11 hours ago

Teach fish how to swim. But, if somebody tells you that your and you are are not the same, don't respond with this idiom!
– mahmud koya
11 hours ago

7

7

Possible duplicate of "Teaching fish to swim"
– Mari-Lou A
10 hours ago

Possible duplicate of "Teaching fish to swim"
– Mari-Lou A
10 hours ago

4

4

and also Idiom for explaining something to someone who clearly knows the topic (probably better than you)
– Mari-Lou A
10 hours ago

and also Idiom for explaining something to someone who clearly knows the topic (probably better than you)
– Mari-Lou A
10 hours ago

1

1

and also english.stackexchange.com/questions/465018/…
– michael.hor257k
8 hours ago

and also english.stackexchange.com/questions/465018/…
– michael.hor257k
8 hours ago

1

1

I must say, "Teach fish how to swim" is not very current / not popular at all. in both US / BR
– Fattie
5 hours ago

I must say, "Teach fish how to swim" is not very current / not popular at all. in both US / BR
– Fattie
5 hours ago

 | 
show 4 more comments

3 Answers
3

active

oldest

votes

up vote
9
down vote

Teaching your grandmother to suck eggs is a classic.

look it up in Wikipedia if you wish

share|improve this answer

answered 11 hours ago

Ricky

13.5k43074

add a comment | 

up vote
1
down vote

One word for this concept with a lot of currency is mansplaining. It’s well-known enough that I’ve even heard it humorously applied when a woman is doing it.

share|improve this answer

answered 1 hour ago

Ernest Friedman-Hill

2,87111620

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  Wouldn't that be ma-amsplaining?
  – Syzygy
  1 hour ago
  

  
  
  
  

add a comment | 

up vote
-1
down vote

Preaching to the choir is a very common one.

share|improve this answer

answered 2 hours ago

Alex

1

New contributor

Alex is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  No. Preaching to the choir means trying to convince the convinced, not educate the educated.
  – michael.hor257k
  2 hours ago
  

  
  
  
  

add a comment | 

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3 Answers
3

active

oldest

votes

3 Answers
3

active

oldest

votes

active

oldest

votes

active

oldest

votes

up vote
9
down vote

Teaching your grandmother to suck eggs is a classic.

look it up in Wikipedia if you wish

share|improve this answer

answered 11 hours ago

Ricky

13.5k43074

add a comment | 

up vote
9
down vote

Teaching your grandmother to suck eggs is a classic.

look it up in Wikipedia if you wish

share|improve this answer

answered 11 hours ago

Ricky

13.5k43074

add a comment | 

up vote
9
down vote

up vote
9
down vote

Teaching your grandmother to suck eggs is a classic.

look it up in Wikipedia if you wish

share|improve this answer

answered 11 hours ago

Ricky

13.5k43074

Teaching your grandmother to suck eggs is a classic.

look it up in Wikipedia if you wish

share|improve this answer

answered 11 hours ago

Ricky

13.5k43074

share|improve this answer

share|improve this answer

answered 11 hours ago

Ricky

13.5k43074

answered 11 hours ago

Ricky

13.5k43074

answered 11 hours ago

Ricky

13.5k43074

13.5k43074

add a comment | 

add a comment | 

up vote
1
down vote

One word for this concept with a lot of currency is mansplaining. It’s well-known enough that I’ve even heard it humorously applied when a woman is doing it.

share|improve this answer

answered 1 hour ago

Ernest Friedman-Hill

2,87111620

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  Wouldn't that be ma-amsplaining?
  – Syzygy
  1 hour ago
  

  
  
  
  

add a comment | 

up vote
1
down vote

One word for this concept with a lot of currency is mansplaining. It’s well-known enough that I’ve even heard it humorously applied when a woman is doing it.

share|improve this answer

answered 1 hour ago

Ernest Friedman-Hill

2,87111620

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  Wouldn't that be ma-amsplaining?
  – Syzygy
  1 hour ago
  

  
  
  
  

add a comment | 

up vote
1
down vote

up vote
1
down vote

One word for this concept with a lot of currency is mansplaining. It’s well-known enough that I’ve even heard it humorously applied when a woman is doing it.

share|improve this answer

answered 1 hour ago

Ernest Friedman-Hill

2,87111620

One word for this concept with a lot of currency is mansplaining. It’s well-known enough that I’ve even heard it humorously applied when a woman is doing it.

share|improve this answer

answered 1 hour ago

Ernest Friedman-Hill

2,87111620

share|improve this answer

share|improve this answer

answered 1 hour ago

Ernest Friedman-Hill

2,87111620

answered 1 hour ago

Ernest Friedman-Hill

2,87111620

answered 1 hour ago

Ernest Friedman-Hill

2,87111620

2,87111620

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  Wouldn't that be ma-amsplaining?
  – Syzygy
  1 hour ago
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  Wouldn't that be ma-amsplaining?
  – Syzygy
  1 hour ago
  

  
  
  
  

1

1

Wouldn't that be ma-amsplaining?
– Syzygy
1 hour ago

Wouldn't that be ma-amsplaining?
– Syzygy
1 hour ago

add a comment | 

up vote
-1
down vote

Preaching to the choir is a very common one.

share|improve this answer

answered 2 hours ago

Alex

1

New contributor

Alex is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  No. Preaching to the choir means trying to convince the convinced, not educate the educated.
  – michael.hor257k
  2 hours ago
  

  
  
  
  

add a comment | 

up vote
-1
down vote

Preaching to the choir is a very common one.

share|improve this answer

answered 2 hours ago

Alex

1

New contributor

Alex is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  No. Preaching to the choir means trying to convince the convinced, not educate the educated.
  – michael.hor257k
  2 hours ago
  

  
  
  
  

add a comment | 

up vote
-1
down vote

up vote
-1
down vote

Preaching to the choir is a very common one.

share|improve this answer

answered 2 hours ago

Alex

1

New contributor

Alex is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

Preaching to the choir is a very common one.

share|improve this answer

answered 2 hours ago

Alex

1

New contributor

Alex is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

share|improve this answer

share|improve this answer

answered 2 hours ago

Alex

1

New contributor

Alex is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

answered 2 hours ago

Alex

1

answered 2 hours ago

Alex

1

1

New contributor

Alex is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

New contributor

Alex is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

Alex is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  No. Preaching to the choir means trying to convince the convinced, not educate the educated.
  – michael.hor257k
  2 hours ago
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  No. Preaching to the choir means trying to convince the convinced, not educate the educated.
  – michael.hor257k
  2 hours ago
  

  
  
  
  

5

5

No. Preaching to the choir means trying to convince the convinced, not educate the educated.
– michael.hor257k
2 hours ago

No. Preaching to the choir means trying to convince the convinced, not educate the educated.
– michael.hor257k
2 hours ago

add a comment | 

 

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