Conjugación del verbo inglés
MUST OBSERVE

Verbo regular: observe - observed - observed

Afirmación

Forma simple	Forma con V-ing
I must observe you must observe he must observe we must observe you must observe they must observe	I must be observing you must be observing he must be observing we must be observing you must be observing they must be observing
Perfecto	Perfecto con V-ing
I must have observed you must have observed he must have observed we must have observed you must have observed they must have observed	I must have been observing you must have been observing he must have been observing we must have been observing you must have been observing they must have been observing

Negación

Forma simple	Forma con V-ing
I mustn't observe you mustn't observe he mustn't observe we mustn't observe you mustn't observe they mustn't observe	I mustn't be observing you mustn't be observing he mustn't be observing we mustn't be observing you mustn't be observing they mustn't be observing
Perfecto	Perfecto con V-ing
I mustn't have observed you mustn't have observed he mustn't have observed we mustn't have observed you mustn't have observed they mustn't have observed	I mustn't have been observing you mustn't have been observing he mustn't have been observing we mustn't have been observing you mustn't have been observing they mustn't have been observing

Forma interrogativa

Forma simple	Forma con V-ing
must I observe? must you observe? must he observe? must we observe? must you observe? must they observe?	must I be observing? must you be observing? must he be observing? must we be observing? must you be observing? must they be observing?
Perfecto	Perfecto con V-ing
must I have observed? must you have observed? must he have observed? must we have observed? must you have observed? must they have observed?	must I have been observing? must you have been observing? must he have been observing? must we have been observing? must you have been observing? must they have been observing?

Forma interro-negativa

Forma simple	Forma con V-ing
mustn't I observe? mustn't you observe? mustn't he observe? mustn't we observe? mustn't you observe? mustn't they observe?	mustn't I be observing? mustn't you be observing? mustn't he be observing? mustn't we be observing? mustn't you be observing? mustn't they be observing?
Perfecto	Perfecto con V-ing
mustn't I have observed? mustn't you have observed? mustn't he have observed? mustn't we have observed? mustn't you have observed? mustn't they have observed?	mustn't I have been observing? mustn't you have been observing? mustn't he have been observing? mustn't we have been observing? mustn't you have been observing? mustn't they have been observing?