The conditional tense is the tense you use to express something that might happen i.e I will swim, I will run.
An easy way to form this tense is using the phrase Je voudrais + infinitive. To say, I would like to + the infinitive of the verb. An example being, I would like to walk.
To use other verbs. You use the pronouns Je, tu, il/elle, nous, vous, ils/elles/ont + the infinitive of the verb (to run, courir) + the endings ais, ais, ait, ions, iez, aient
So I will watch would be
Je = I
The infinitive of the verb watch = Regarder
The ending = ais
Put this all together it will be Je regarderais