When we introduce a sentence with a verb that expresses doubt or uncertainty, whether it be affirmative or negative, it is followed by the subjunctive. For example:
- dudo que... (I doubt that...)
- es posible que... (It is possible that...)
- es probable que... (It is probable that...)
These are negative examples:
Here are more common doubt or uncertainty phrases which apply this rule:
- Es dudoso que... (It is doubtful that...)
- Es imposible que... (It is impossible that...)
- Es improbable que... (It is improbable that...)
- Temo que... (I suspect that...)
Have a look and listen to these examples which use the subjunctive:
However, if the expressions introduce a quality of certainty, we need to use Modo indicativo. For example compare:
- Estoy segura de que has llegado a tiempo
- No estoy segura de que hayas llegado a tiempo.
Notice how in all the sentences using the subjunctive above the subject of the introductory phrase is not the same as the subordinate phrase:
dudo= I doubt / tengan= they have
This is a condition that must be met in order to use the subjunctive.
However, if the subject in the main and subordinate phrase is the same, we would use the infinitive instead:
Notice there is no que in this case.
- Using the subjunctive with negative opinion phrases
- Using the subjunctive with verbs that express "wish" and "feeling"
- Using the subjunctive with impersonal expressions
- Modo subjuntivo