Conjugación del verbo inglés
COULD THUNDER

Verbo regular: thunder - thundered - thundered

Afirmación

Forma simple	Forma con V-ing
- - it could thunder - - -	- - it could be thundering - - -
Perfecto	Perfecto con V-ing
- - it could have thundered - - -	- - it could have been thundering - - -

Negación

Forma simple	Forma con V-ing
- - it couldn't thunder - - -	- - it couldn't be thundering - - -
Perfecto	Perfecto con V-ing
- - it couldn't have thundered - - -	- - it couldn't have been thundering - - -

Forma interrogativa

Forma simple	Forma con V-ing
- - could it thunder? - - -	- - could it be thundering? - - -
Perfecto	Perfecto con V-ing
- - could it have thundered? - - -	- - could it have been thundering? - - -

Forma interro-negativa

Forma simple	Forma con V-ing
- - couldn't it thunder? - - -	- - couldn't it be thundering? - - -
Perfecto	Perfecto con V-ing
- - couldn't it have thundered? - - -	- - couldn't it have been thundering? - - -