Present English Tenses

PRESENT TENSE

The simple present is used:

1. to express habits, general truths, repeated actions or unchanging situations, emotions and wishes:

I smoke (habit); 

I work in London (unchanging situation); 

London is a large city (general truth)

2. to give instructions or directions:

You walk for two hundred meters, then you turn left.

3. to express fixed arrangements, present or future:

Your exam starts at 09.00

4. to express future time, after some conjunctions: after, when, before, as soon as, until:

He'll give it to you when you come next Saturday. 

How to Write English Sentences - Introduction

Before you write an English sentence you have to get organized.

The first stage of organization is choosing the single or complete thought that you
are stating, describing, explaining or asking. The thought should include 1. a subject,
and 2. an action or state of being.

Link to How to Write English sentences

http://www.sentencemaster.ca/howtowritesentences.html