First off, since you will be commenting on the level of someone's education, you'll usually want to be cautious in the words you choose, since no one would like their level of intelligence to be made fun of! ;)
Anyways, since you are looking for a polite way to express this, I probably wouldn't lean in the direction of ignorante
or inculto
. These words aren't totally rude per se, but they might come off as being a little too blunt. You could probably get away using them in a joking or playful manner, but caution is still advised. Other words that could probably fall into this category might include bruto
(brute), and necio
(roughly: uneducated fool.)
Now, falto(a) de educación
would probably work, but it could also be interpreted in a way similar to maleducado
, that is rude
. It would really depend on the context.
In my humble opinion, I think that a good (and unambigious) way to express the lack of education
, would be to use an expression meaning without
. In this case the preposition sin
or a negative of the verb tener
work well. These patterns also allow you to specify the type of education a person lacks (e.g. escuela secundaria
(high school), colegio
(college), etc.)
For Example:
- Ella está sin colegio.
- Ella no tiene (un título del) colegio.
She doesn't have a college education.
That more-or-less should cover all the basic and general expressions that would be used. In general, the same principles that you would use to choose how you'd express this in English will apply here. Just try to be sensitive and smile. Hope this helps! :)