-и/-ите

The Russian imperative allows you to give orders, advice, or instructions. While there are other endings like -й or -ь, the -и/-ите pattern is used in specific phonetic environments.

1. The Stressed Ending Rule
If the stem ends in a consonant and the 1st person singular (я form) has the stress on the final vowel, the imperative will end in a stressed -и. To find the stem, drop the ending from the 3rd person plural (они form). This rule also applies to verbs ending in -ить with a preceding vowel, like поить (to give drink).

• говорить (to speak) -> они говорят -> говори / говорите
• писать (to write) -> они пишут -> пиши / пишите

2. The Consonant Cluster Rule
If the verb stem ends in two or more consonants, you generally use -и even if the stress is on the stem in the я form. In these cases, the -и is usually unstressed. A notable exception is сыпать (to pour/scatter), which becomes сыпь.

• крикнуть (to shout) -> они крикнут -> крикни / крикните

3. The -ь and -ей Exceptions
If the stem ends in a single consonant and the stress is on the stem in the я form, the ending is -ь. Always use the они form to find the stem to avoid consonant mutations (e.g., готовить (to cook) -> они готовят -> готовь). Additionally, monosyllabic verbs with shifting stems like пить (to drink) or лить (to pour) take -ей (пей, лей) instead of -и.

4. The 'вы-' Prefix
Perfective verbs with the prefix вы- always pull the stress to the prefix. They still take the -и/-ите ending if the original non-prefixed verb would have taken it.

• выписать (to write out/prescribe) -> они выпишут -> выпиши / выпишите

5. Reflexive Verbs
For reflexive verbs, the reflexive particle attaches after the imperative ending. Use -ись for the singular and -итесь for the plural/formal.

• садиться (to sit down) -> они садятся -> садись / садитесь

6. Politeness
The singular -и form is strictly informal and should only be used with people you address as ты. Using it with strangers or in formal situations is impolite, even if you add пожалуйста. For adults, strangers, or groups, you MUST use the plural/formal -ите form.

7. Highly Irregular Forms
Some essential verbs break these phonetic rules entirely and must be memorized: лечь (to lie down) -> ляг / лягте, есть (to eat) -> ешь / ешьте, and ехать (to go by vehicle) -> поезжай / поезжайте.

8. Negative Commands
When telling someone not to do something, you almost always use не with the imperfective aspect (negative imperative with the imperfective), even if the positive command was perfective (e.g., не пиши, not не выпиши).