Open a sentence with:

parts of speech

a subordinating conjunction (when, while, where, as, since, if, although)
: While the sun was out, (aka clausal)

a preposition
: Under the table,

an ing word (participial phrase-present) Action is less direct. Often overused. (McCowan)
: Taking off his hat, he sat down.

an ed word (participial phrase-past)
: Disappointed by the weather, // state of being or feeling

an ly word (adverbial phrase)
: Slowly, //state of mind or way, transitional structure

an absolute phrase
: Hands shaking, she opened the door.

a perfect infinitive phrase
: To have arrived on time, I would have had to come by plane.

an adjective
: Fearful, the cat fled through the yard.

a verb
: Answered Helen, “I do not want to go.”

verb proceeds noun (anastrophe)
: Along the wall crawled the spider.

Open a sentence with:

ideas

a transition that compares
: Despite this

a transition that states cause and effect
: Obviously,

a transition that shows time
: After a while,

Start with When
: Before the sun rose

Start with Where – Where, S V.
: Inside
: Below
: Above
: On the shore

Don’t open a sentence with:

Try to limit these openers and start instead with a noun as the subject.