Pull database entry string from association in Marshmallow

Question

I have a sqlalchemy database association between Type and Language and am trying to get marshmallow to pull a specific column string from Language but it only wants to give me the object of Language converted to a string.

Here is my TypeSchema

class TypeSchema(ma.SQLAlchemySchema):
    class Meta:
        model = Type
        ordered = True
    #If I put ma.String().language it gives me an error
    languages = ma.List(ma.String(), dump_only=True, many=True)

This produces this json output

    {
      "languages": [
        "<api.models.Language object at 0x000001C15E60A320>"
      ]
    }

This is my desired output

    {
      "languages": [
        "en", "sp", "de"
      ]
    }

Here is my models.py

class Language(Updateable, db.Model):
    __tablename__ = 'language'

    id = sqla.Column(sqla.Integer, primary_key=True)
    language = sqla.Column(sqla.String(2), nullable=False)

    type_id = sqla.Column(sqla.Integer, sqla.ForeignKey(Type.id), index=True)
    type = sqla_orm.relationship('Type', back_populates='languages')


class Type(Updateable, db.Model):
    __tablename__ = 'type'

    id = sqla.Column(sqla.Integer, primary_key=True) 
    languages = sqla_orm.relationship('Language', back_populates='type')