must thunder
Verbo regular: thunder - thundered- thundered

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

Negación 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
-
-
it must not thunder
-
-
- 	-
-
it must not be thundering
-
-
- 	-
-
it must not have thundered
-
-
- 	-
-
it must not have been thundering
-
-
- 	

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

Forma interro-negativa 	
Forma simple 	Forma con V-ing 	Perfecto 	Perfecto con V-ing 	
-
-
must it not thunder?
-
-
- 	-
-
must it not be thundering?
-
-
- 	-
-
must it not have thundered?
-
-
- 	-
-
must it not have been thundering?
-
-
-