1. KISS: Keep Instructions Short & Simple
Use 1 word and a gesture if possible. Show and tell. Don't clutter up your instructions with social niceties -- every single word that you speak creates a cognitive load for our beginning learners.
Watch this Jo Gakonga video for great demonstrations of how not to give instructions.
Try to avoid using idioms, slang, or popular cultural references, unless you are specifically teaching these are part of a lesson. Describing an activity as "a piece of cake" or "easy-peasy" just creates unnecessary confusion.
2. Keep vocabulary in context
One of the things that makes English so interesting for poets and creative writers and so frustrating for beginning learners that one word can have many meanings. When introducing new vocabulary, introduce the meaning that relates to the context in which the vocabulary is being used.
For example, in a unit on health and body parts, you'll introduce the word "body". You'll give examples and practice use of the word in the context of health and body parts. Even though these may be interesting to you as an advanced English speaker, you should not introduce other uses of "body" such as a body of water, a car body, a student body president, the thick body of your hair, or everybody, anybody, and nobody, until each such use is relevant to the lesson that you're teaching.
3. Consider what foundational knowledge a lesson requires
What foundational information or skills do learners need in order to understand the lesson that you're about to give? You may want to check for that foundational information before starting your lesson, to save both you and your learners time and frustration.
For example, in order to teach the rule for the pronunciation of the final -ed in regular simple past verbs, learners need to know:
What a simple past verb is (or simply that you are talking about actions that already happened),
What a syllable is (a "beat" or a "clap" in a word), and
The difference between voiced and unvoiced (or whispered) consonant sounds.
4. Check for understanding
How do you know if learners have understood your instructions or a concept that you have presented? Don't ask "Do you understand?" Learners may not realize that they don't understand, may not feel comfortable admitting that they don't understand, and may not have the vocabulary to express their lack of understanding.
Instead, ask very simple yes/no or this-or-that questions to check for understanding. These question types check for recognition, but don't require students to recall or produce new language.
For example, if you want students to practice naming their first language (such as when asking for an interpreter), you can ask "I speak ... Portland, yes?" Or "I speak ... English or Amy?"
Now it's your turn. Try this mini-course (about 10 minutes) to see if you can identify ways to simplify and clarify communication with beginning English learners.