Language Analysis:
It is because is used in the following situations:

To introduce an explanation of cause and effect use It is because:

• It is because of parents like her that our school is such a wonderful place. (like= similar to)
• It is because of my close association with the organisation that I know all the good that it does.
• It is because the body is a machine that education is possible.
• It is because workers today produce far more than those in the past that we have a higher standard of living.

To refer back to a cause, then give an effect, use it is because of this:

• These countries’ economies are in great turmoil and it is because of this that pollution creates a huge problem.
• I know you. I understand you, and it is because of this that I love you.
• A black coat appears black because it absorbs all the wavelengths of visual light that fall on it and no light is reflected into the eye from that object. It is because of this that black clothes become hotter on a sunny day than white ones.

Structures:
Cause + ‘and’ + ‘it is because of this that’ + effect
Cause + ‘.’ + ‘It is because of this that’ + effect

To give an effect first, then explain the cause, use this is because:

• Out in space, the sky looks black, instead of blue. This is because there is no atmosphere.
• As the sun begins to set, the light must travel farther through the atmosphere before it gets to you. More of the light is reflected and scattered. As less reaches you directly, the sun appears less bright. The colour of the sun itself appears to change, first to orange and then to red. This is because even more of the short wavelength blues and greens are now scattered. Only the longer wavelengths are left in the direct beam that reaches your eyes.
• Agents often work more than 40 hours a week. They must often work in the evenings or on weekends. This is because most buyers and sellers are free only at those times.

To answer questions, use it is because, this is because, or because:

• How can it be that an “awesome” God knows me by name and loves me without reservation? It is because He created me.
• So why is Bush taking on the thankless issue of immigration? I believe it is because he sees the consequences for all Americans of our current dysfunctional policy.
• Teens seem to have a need to feel that fear, as evidenced by the popularity of shocker, gross-out, supernatural and altogether scary books. Is it that the good guys and bad guys are easier to tell apart? Or maybe it is because those vampires and werewolves go through physical transformations that make puberty feel like a bump in the road?
• Why are most large-sized tumours treated by removal of the eye? This is because the amount of radiation required to kill a tumour which fills most of the eye, is just too much for the eye to stand.
• “Why are you doing that?” “Because I like it.”

In 'if ' and 'when' sentences use it is because:

• If I look confused it is because I am thinking.
• If we have no peace, it is because we have forgotten that we belong to each other.
• When consumers complain that prices of CDs are too high it is because they are.

• Because or Due to the fact that - an explanation and an exercise.
• Cause and Effect - this exercise introduces the vocabulary and grammar needed to describe causes and effects. Includes an exercise.