Does tandis que need the subjunctive or is it indicative? This is a common question among French students and there's an easy answer. The primary thing you must keep in mind is that the subjunctive relies on uncertainty and there is none in tandis que, which means "while."
Does Tandis Que Require the Subjunctive?
No, tandis que does not take the subjunctive. Tandis que means "while" or "as"; something is happening at the same time as something else.
- Je cuisine tandis qu'elle nettoie.
- I cook while she cleans.
The general rule that we are taught about the subjunctive in French is that there needs to be a level of ambiguity to the statement. In the case of our example, there is no question that I am cooking or that she is cleaning and that the two actions occur at the same time.
- Elle faisait ses devoirs tandis que je lisais un livre.
- She was doing her homework while I was reading a book.
Likewise, few people could dispute the following statement: Even though the cause of the fire may be in question, the fact that I was in bed when it started is not a matter of debate.
- Le feu a commencé tandis que j'étais au lit.
- The fire started while I was in bed.
This is the same issue that arises with pendant que, which also means "while." The two phrases are stating a fact and, therefore, are indicative.
- Il tond la pelouse tandis qu'elle plante des fleurs.
- He mows the lawn while she plants flowers.
- Il attend pendant qu'ils réparent la voiture.
- He is waiting while they repair the car.