PRESENT SIMPLE - action or condition which is permanent or habitual.
PRESENT CONTINUOUS - action or condition which is happening now and is incomplete.
Normally, stem of verb with "s" or "es" added for 3rd person singular.
There are only 4 irregular verbs in the present simple (and two are because of pronunciation). Full list here.
Use the present continuous tense with the appropriate “to be” form and a dynamic verb. A dynamic verb shows action and/or process. For example,
Do not use the present continuous tense with stative verbs. Stative verbs show a state of being that does not show qualities of change. These verbs can stay in the simple present. For example,
Here, the stative verb "to prefer" shows opinion, and therefore should not be used with the present continuous.
Stative verb categories include emotion (to love), possession (to belong), and thoughts (to recognise), and none of these should use the present continuous form.
Some verbs can be both dynamic and stative! Think about the verbs to be and to think. In its dynamic form, the verb to be can show action:
But in its stative form, the verb to be is awkward if conjugated in the present continuous.
Here are some more examples:
SENSES / PERCEPTION
OPINION
MENTAL STATES
EMOTIONS / DESIRES
MEASUREMENT
OTHERS
EXCEPTIONS
Perception verbs (see, hear, feel, taste, smell) are often used with can: : I can see... These verbs may be used in the continuous form but with a different meaning
REMEMBER that auxiliary verbs (except do, be and have) take no -s in the third person singular. The main modal auxiliary verbs are can, could, may, might, must, shall, should, will, and would (the semi-modal verbs - ought to, used to - also do not change form in the simple present).