An infinitive is the form of the verb such as "to drink" in English. In Spanish, the infinitive always ends in -ar, -er, or -ir.

The present tense endings depend on who is doing the drinking. Usually it helps to remember them in the order of 1st, 2nd, 3rd person singular, then 1st, 2nd, 3rd person plural. (In other words , I, you, he/she/it, we, you all, they).

So, you could think to yourself: -o, -es, -e, -emos, -éis, -en (that's for -er verbs only! The others are similar).

Don't worry, as you practice more, the endings will feel more natural. Try working on some of the beginner lessons for the present tense. Good luck!

Here's a thought. Take the tune to "There was a farmer who had a dog and Bingo was his name -o" and put these words to it:

There was a student who had an infinitive he had to conjuga-ate!

-o.-as, a-, amos, áis....-o, -as, -a -amos, áis...-o, -as, -a -amos, -áis and -an was the way!

Do that for all three verb endings; sing several times a day, and you will have them.

i get 1, 2, 3 person mixed up and I will be practicing.

I would encourage you to look for patterns. Amongst the 'regular' verbs, they pretty much all conjugate with the exact same endings. I have created a poster with about 130 of the most common Spanish verbs. You can see these verb ending patterns and after studying a few verbs you really start getting the hang of conjugating 'on the fly'.

I've had to memorize a lot of the irregular verbs, but even then there are enough patterns to make it easy.

I have these verbs in an Excel spreadsheet if you'd like to have a copy.