Adjectives: BORED vs. BORING

What is the difference in meaning between these two adjectives?

• a boring student
• a bored student

The first says something insulting about the student. If you want to describe a student who would rather be somewhere else, you should use the second.

A student might describe himself as bored and one of his lessons as boring. It is not a coincidence that these look like forms of the verb bore. Consider the following sentence: 

• The lesson bored the student.

If we wanted to focus on the role of the subject or the role of the object, we could rephrase it as one of the following:

• The lesson was boring. [progressive]
• The student was bored. [passive]

The subject (the lesson) of the active sentence can be described as boring and the object (the student) can be described as bored. It is the same when they are used as attributive adjectives:

• The boring lesson
• The bored student

Here are some other verbs that follow the same pattern:

A conversation at noon

Tenses and aspect are among the most difficult things to learn in any language, so I've made a pretty chart to simplify the whole thing. It includes an example of a conversation that includes each form at least once.

Click to enlarge!

UPDATE:
It helps if you look at which time phrases you can use with each form (left side of the chart). For example:

The race started at 10am. [the simple past]
The race has started now. [has is present tense, so it is about the past of the present (i.e., a time before now)]
The race had started at 11am. [had is past tense, so it is about the past of the past (i.e., a time before 11am)]

If it is now 12pm, you can't say:

WRONG: The race has started at 10am. [has is present tense, but 10am is in the past, so it doesn't make sense]

If you want to attach a time phrase to start instead of have, use the simple past form.

Uses of the simple present tense

Dynamic verbs
With dynamic verbs (i.e., verbs that describe actions and events), the simple present tense normally has a habitual meaning so can be used with adverbials such as every day and often.

The Sun rises in the east (every day).

To talk about an event that is happening right now, you need to use the progressive -ing form of the verb instead.

The Sun is rising (right now).

Stative verbs
With stative verbs (i.e., verbs that describe states and relations), the simple present tense can't be used with a habitual meaning. Instead, it indicates a state or relation that holds in the present, much as the progressive -ing form is used to indicate the present with dynamic verbs.

I like/love/want/need you.
I come from Berlin.

Stative verbs do not always have a progressive -ing form. When they do, it often forces a dynamic meaning.

WRONG: I am coming from Berlin. [come from in the sense of where a person grew up]
RIGHT: I am coming home (right now). [come in the sense of moving towards]

The place a person comes from is not something that can change, but for states that are changeable such as where a person lives, an -ing form can sometimes be used, particularly when the state is new or likely to change soon:

I live in Berlin. [no comment about how permanent this is]
I am living in Berlin. [suggests that the speaker has moved to Berlin recently or that they might not stay there]

Some other examples of stative verbs are believe, know, agree, appear, seem, contain, include, consist, exist, belong and cost.