I suppose to make this more of a grammar entry, I will talk a bit about potential conjugation, as in "You CAN'T do that", vs regular conjugation/dictionary form ("You (will) do that"). Basically:
For -る verbs: Take of the -るand add -られる. 食べる ＝＞ 食べ ＝＞ 食べられる
For all other verbs: Take of the -うand add -える. 行く ＝＞ 行ける
The irregular するbecomes できる. 来るbecomes 来られる.
From this point, all the verbs are -る verbs. So, if you wanted to change it to the more formal -ます form:
食べられる ＝＞ 食べられます ・・・ 行ける ＝＞ 行けます
However, I often heard people dropping the -らpart of the -るverb conjugation. I've heard that this may be naturally happening because the potential and causative form of -るverbs are identical, and people naturally want to differentiate them. Thus:
When speaking I think you will mostly hear -れるinstead of -られる; but when writing make sure you use the technically correct form.