You're welcome.
While it's true that a dictionary only provides the infinitive form of a verb, there are a couple of ways to find out the infinitive if you only have a conjugated verb to go on.
I like
wordreference.com and
conjugator.reverso.net.
On either site, you can enter the conjugated form of the verb and get a full verb chart, which includes the infinitive.
You can also go to the homepage of
wordreference.com and enter the conjugated verb (after selecting the language source and target). It'll bring up the infinitive's entry, as expected, but will also tell you (in Spanish) what conjugation you entered, so you can find it more easily in a verb chart.