Show tags for each entry I have one tag for each entry.

 - Entry1
     Tag1
 - Entry2
     Tag2


Now I want to show them in the title of each entry. But it doesn't work.

{% for entry in craft.entries.section('mainEntry').limit(4) %}
{% set tag = entry.mainEntryTag.first() %}
  &lt;h2&gt;{{ tag }} {{ entry.title }}&lt;/h2&gt;
{% endfor %}


This results in displaying only the globally first tag:

- Entry1
     Tag1
- Entry2
     Tag1


If I just write: {% set tag = entry.projektart %} I get the error: Object of class Craft\ElementCriteriaModel could not be converted to string

How can I get to current entry tag?
You're very close. Change "set tag" to "set tags" so you have:

{% set tags = entry.projektart %}


And then loop through the tags:

{% for tag in tags %}
    {{ tag }}
{% else %}
    No tags found
{% endfor %}


You could also simplify this and instead of setting the "tags" variable you could write the following:

{% for tag in entry.projektart %}