No distinction between read and read (past) in pos tagger

[mflerackers]

Here read is R IY D => I'd like to read a book
Here read is R EH D => I read a book yesterday

getPhonemes always returns R EH D of course as it doesn't know the context.

So I tried using the pos tagger to know which one to use, but it gives me vbp instead of vpd for the past tense read.