He realized that he needs...

[leo12345]

"He realized that he needs to do something about it urgently."
vs
"He realized that he needed to do something about it urgently."

I understand that the second version is more grammatically correct, but it still seems to me that the first one is also correct.

Can I use present (needs) with past (realized)?

 

[Skrej]

Yes, it depends upon whether the thing needed has been done or not.

If he still needs to do it, you could use 'needs'. If he realized it, but has already taken care of it, then use 'needed'.

 

[leo12345]

Thanks you , but it is still unclear to me.
Some things last forever, for example how about this one:

"He thought that dancing IS a hard thing" or "He thought that dancing WAS a hard thing"

“I used to think that fishes don't know how to speak.” or “I used to think that fishes didn't know how to speak.”

Which one is right to write?

 

[MikeNewYork]

Since you are talking about thinking, the tense should be determined by what the person currently thinks.

 

[Raymott]

“I used to think that fishes don't know how to speak.” or “I used to think that fishes didn't know how to speak.”
Which one is right to write?

'"Fishes don't know how to speak", I used to think'. You are reporting this. Back-shifting will always be correct in reported speech (I'd use your second version), but you can use either.

 

[Eckaslike]

(I'm a first language speaker of BrE from England. But not a Teacher).

"He thought that dancing WAS a hard thing": Because he was thinking in the past.

“I used to think that fishes didn't know how to speak.” To me this sounds better as the tenses agree, but should actually be "I used to think that fish didn't know how to speak", because fish is one of those peculiar English words where the singular name is the same as the plural. "One fish, two fish, three fish etc". The same goes for sheep. "One sheep, two sheep, three sheep etc". But for most things you would add an "s" or an "es" ending for plurals, such as " one cat, two cats, three cats". I'm not sure if AmE or other forms of English spoken elsewhere follow this rule.

 

[Raymott]

You're kidding, right? You don't know that 'fishes' is also a correct plural for 'fish'? If you're going to go out on a limb like this, you should probably check a dictionary first.

Joy to the fishes in the deep blue sea
Joy to you and me

 

[MikeNewYork]

And let's not forget "sheeps".

 

[Eckaslike]

Hi Raymott. Sorry, you are right. But in the UK the word "fishes" would mainly be used in poetry. For example we wouldn't say "I'm going to the shops to get some fishes". It would be fish however many we were buying.

 

[MikeNewYork]

But one might say "there are many fishes in the sea". In your shop analogy "fish" is uncountable, but it not always so.

 

[Eckaslike]

Point taken MikeNewYork and Raymott. My fixed view on that was probably caused by what I was brought up to say. Next time I will check a dictionary before being so emphatic. Sorry both!