Which verbs have 辞書形 (dictionary forms) that look like ~ます conjugations?

Question

I recently confused 励{はげ}ます for the ~ます form of 禿{は}げる.

Although this actually lead to a rather amusing conversation, I'm wondering if there are other examples of this to watch out for?

Answer 1

Looking at EDICT following Derek, I found two other examples, but in these cases two interpretations are not drastically different as your case. Both are compound words where the second component is 増す (ます; to increase).

• 建て増す (たてます; to extend (a building)) has the same pronunciation as 建てます, the polite form of 建てる (たてる; to build) and also as 立てます, the polite form of 立てる (たてる; to make (sthg.) stand; can stand). There are many other verbs of the pronunciation たてる whose polite forms are pronounced as たてます, too. Basically all of them are made from verbs whose pronunciation is たつ by deriving transitive verbs or deriving 可能動詞.
• 積み増す (つみます; to expand (a budget etc.)) has the same pronunciation as 積みます, the polite form of 積む (つむ; to pile). There are several other verbs of the same pronunciation つむ (摘む and 詰む), and their polite forms are also pronounced as つみます.

Answer 2

While YOU's examples all end in ～ます, you can easily see that they are not proper ～ます verbs, because they don't match the conjugation patterns for either type of verb.

But this is an interesting question, so I wrote a quick python script to conjugate 3,100 verbs from EDICT and compare the ～ます form of every verb to the plain form of every other verb. 励ます (matching either 禿げます or 剥げます) is the only verb that turned up as a "false positive ～ます". So assuming my script is working correctly, you've found the only pair that exists.