Its and it's, and prepositional phrases

Its or it's? The most common mistake in written English, and easy to fix.

• it's (with an apostrophe) = it is or it has: 'It's getting dark outside.'
• its (no apostrophe) = belonging to it: 'The dog wagged its tail.'

Why no apostrophe in 'its'? Because it belongs with his, hers, ours, yours, theirs, and none of those has an apostrophe either.

The same pattern:

• you're = you are ('You're going to love this book') / your = belonging to you ('Can I have one of your books?');
• they're = they are ('They're coming on the field trip') / their = belonging to them ('We should contact their manager').

The test: say the long form. 'The tree lost it is leaves'? Nonsense, so write its. 'It is important to drink water'? Makes sense, so write it's.

Prepositional phrases. A group of words that begins with a preposition (in, on, with, at…) and includes a noun or pronoun:

• in today's fast-paced world;
• on the telephone;
• with great, abiding pleasure;
• at a certain time;
• with equal respect and love.

They tell you when, where, how, why, in which direction, or the relationship between things. They make a plain sentence clear: 'The children played' → 'The children played happily in the park near our house.'

Jumbled sentences: keep each phrase together as one block, and the sentence falls into place: 'The dog / barked loudly / at the strangers / walking by the house.'